Life with Lord Ashdown is no Werther's Originals advert

He spent his 70th birthday racing his grandson on the ski slopes, and the former Lib Dem leader still has the drive to try to see off his party's critics. Matt Chorley meets Lord Ashdown

(JUSTIN SUTCLIFFE)

It is a disrespectful thief who steals the coffee stash of a peer of the realm. But they are especially foolhardy when the Lord in question is ex-special forces and in urgent need of an injection of caffeine.

Cursing the light-fingered visitor to his refreshments store in his office over-looking Westminster Abbey, Paddy Ashdown is on storming form. A Lib Dem staffer quickly dispatched to make a brew; he fires up his computer, takes two calls, opens post, adds to the bookshelf and rattles off anecdotes about his time in Bosnia almost before he has got his coat off.

Finally settling into a modern blue sofa, he shows no sign of slowing down. Indeed, he believes if he did he would be "dead in a week". He is engrossed in writing his seventh book, on the 70th anniversary of the Special Boat Service – of which he was famously a member – and, later this month, he will publish a review for the Government on humanitarian aid sent to disaster zones. As former party leader, Ashdown remains the wise owl of Lib Dem politics, the go-to for advice and counsel for many in the party made uneasy in recent months by the realities of being in government. So, he has warnings for his Lib Dem colleagues about how they need to "mature" into a party of government, he tears into the government's defence strategy, has a pop at the SAS's bungled foray into Libya, and he fears more blood will be spilt by Gaddafi before the West can intervene.

Flicking between iPad, Apple laptop and iPhone, it is far from obvious that he has just turned 70. "Did I think a lot about my birthday? Yeah. I was absolutely determined not to believe it. I'm never a great birthday man but if you are 70 I suppose it does loom a little large."

He spent his landmark birthday on the ski slopes – with the express aim of proving he can still take on the youngsters. "The purpose of going to France was to beat my grandson. We had five races and I won three." How old is he? "Thirteen. He thinks he can ski." Life in the Ashdown family is no sun-dappled Werther's Originals advert.

Ashdown remains a staunch defender of the coalition – despite disagreeing with the Tory deal "for a couple of hours" last May – regularly taking to the airwaves to insist the Lib Dems were succeeding in power. After an ill-fated bid to strike a deal with Tony Blair's New Labour in the 1990s, his dream of Lib Dems in power has finally been realised.

That is not to say he always toes the line. He is devastating in his assessment of the Ministry of Defence, a department to which some have said he would be well-deployed as Secretary of State. It is, he says, a "dysfunctional organisation" and "not fit for purpose".

The Strategic Defence and Security Review – lambasted by 50 top brass, military experts and politicians in this newspaper last week – was a "flawed process, it lacked political leadership, it descended into an unseemly squabble between the heads of the services to hang on to their most expensive toys instead of a proper result which addressed the defence needs of the country". The decision to axe the Harrier jets was "completely illogical", he adds.

"The MoD is still haemorrhaging money at a very large scale," he warns. "My guess is the government is going to be faced with a very difficult judgement in the near future which is either to spend more on defence – in other words allow it to break its spending review totals – or see cuts further than we have currently seen which is probably unsustainable for a Conservative government. I think this is a very big issue."

All this, as Britain tries to flex its might on the world stage, leading the diplomatic response to events in Libya. After some intelligence failures, notably when William Hague said Gaddafi was on a plane to Venezuela, Ashdown believes the Foreign Office deserves credit for taking an international lead in calling for a no-fly zone.

A detailed package is needed to "persuade Gaddafi to do the right thing, not to continue to slaughter his people". Assistance should also be given to the "people on the streets, arguing for values which we support, to create effective, broadly non-secular but Islamic-based republics".

The moment has not yet arrived for a no-fly zone. "We probably need to have three ingredients before that moment arrives. One, I regret to say, is Gaddafi continues to act as he does, overstepping the mark. If Gaddafi continues along the line he does, that will change international opinion."

There is an historic parallel. "You remember Bosnia? At the start, nobody save for I suppose me, was calling for intervention in Bosnia. At the end, as a result of what the Serbs did, nobody wasn't calling for intervention in Bosnia. This is a dynamic situation, not a static one."

Broader international support is also required, because after Iraq and Afghanistan, "Britain, America and Nato are a toxic brand for Arabs". Any military intervention must include "Arab voices". A wider international coalition is necessary at the UN Security Council, with the Russians and the Chinese "being prepared to at least countenance this, even if not openly support it". Turkey's support will be crucial he says.

The coalition has his "admiration and full support" for taking a lead, and he repeatedly stresses Nick Clegg's central role in the foreign policy discussions.

As the Lib Dems meet in the Deputy Prime Minister's home city of Sheffield this weekend, the polls look bad and the anger targeted at him has again escalated.

Ashdown, who mentored Clegg from former MEP to leadership material, admits he is surprised by the level of ire. "I think some of it is exceedingly unfair. Nick Clegg has shown grace under fire of an order I cannot remember previously in politics." At the height of student demonstrations in London last year, he wrote to Clegg noting the last Liberal politician to have his effigy burnt in Whitehall was Gladstone, over his opposition to the Afghan war. "That comes with the territory, but excreta through the letterbox, all that kind of stuff, it must be very tough for him and Miriam and the family and they have coped extraordinarily well."

Mindful of not sending an "arrogant" message to the party, Ashdown believes they must stick with the coalition in the knowledge that they will not reap the "dividend" of being in government for two years or more. But the switch from a party of opposition to a government defending policy has required a huge mental shift, with which some are still struggling.

"Being a party in government requires a completely different approach but I am astonished at the maturity that, by and large, the party has taken to that. There are some who still want to live in the cloud cuckoo, never-neverland of opposition. I have always said there is no point being a Liberal if you are not prepared to take the risks to put into practice in government and influence the lives of the people of your country, according to your principles. You take risks and make compromises for that."

Things will be done differently in future. Bold election pledges – like the ill-fated student fees abolition – will be avoided. And a new strategy of preserving the party's identity while not undermining the coalition will be shaped over the coming months, including spelling out policy victories over the Tories even if it irritates their coalition colleagues.

"There are some things this government has done which are entirely down to Liberal Democrats – 800,000 people taken out of paying tax, the Pupil Premium, the protection of the schools budget, the reversal of some of the appalling intrusions into our civil liberties and human rights, the fact we all have a choice about the future electoral system. These are down to us. I think we nevertheless have to have some eye towards the cohesion of the Government. If you are a government you have to represent your party but you have to govern for your country."

This commitment will not, though, mean taking a ministerial job. Colleagues and friends have said Ashdown would bring the enthusiasm of a teenager and the wisdom of his years, but he is adamant that he has no desire for another "big job".

One though, has eluded him. "I have done nearly all the things I wanted to do except be prime minister. I am really extremely grumpy that I have never done that job, it will spoil my whole life ..." tailing off into laughter, but there is a hint of truth. This is not a man who understands the word failure.

Curriculum vitae

27 February 1941 Jeremy John Durham Ashdown born in Dehli, India, the eldest of seven children. His father is an officer in the Indian Army, his mother is a military nurse.

1945 The Ashdowns move to Donaghadee, Co Down.

1952 Attends Bedford School. Is nicknamed "Paddy" because of his Irish accent.

1959-72 Serves in the Royal Marines in Northern Ireland, Hong Kong, Borneo and the Arabian Gulf. Joined the elite Special Boat Service.

1962 Marries Jane Courtenay. The couple, right, have two children, a girl and a boy.

1972-76 Works for Foreign Office/MI6 in Geneva.

1975 Joins Liberal Party.

1976 Selected as the Liberal candidate for Yeovil, Somerset.

1979 Loses in the election.

1983 Finally takes Yeovil for Liberals overcoming 11,000 Tory majority to win by 3,000 votes.

1988 Supports Liberal/ Social Democrat merger.

1989 Elected Lib Dem leader.

1992 Admits having an affair with his secretary, Patricia Howard. Memorably dubbed Paddy "Pantsdown"

1999 Resigns the leadership.

2000 Knighted. Resigns as MP the following year and is created Lord Ashdown of Norton sub Hamdon in Somerset.

2002 Appointed High Representative for Bosnia and Herzegovina. Is a prosecution witness in Slobodan Milosevic's trial at the International Criminal Tribunal for the former Yugoslavia at The Hague.