Brown trains his sights on a 'new politics' – with the help of the Lib Dems

The Prime Minister tells <b>Andrew Grice</b> why his commitment to electoral reform is now at the core of Labour's appeal to voters.

Gordon Brown appealed yesterday for a "progressive alliance" of natural Labour and Liberal Democrat supporters to join forces to keep the Conservative Party out of power. In an interview with The Independent, Mr Brown said his new "mission" and "offer" to the British people was the creation of a "new politics" after the MPs' expenses scandal. He revealed a rethink in Labour's strategy in which the party will try to sell its sweeping constitutional reforms to highlight common ground with the Liberal Democrats and convince voters that it can still offer change after 13 years in power.

The move will be seen as an attempt to prevent Labour being damaged by the "Clegg effect", which has transformed the election since the Liberal Democrat leader won last week's first televised debate between the three main party leaders. Mr Brown pointed to the Labour manifesto's pledge to hold a double referendum next year on voting reform for Westminster and an elected House of Lords, which predated the Clegg phenomenon.

"We have to show people we are in the business of the new politics and we have a plan for that as well as the economy," Mr Brown said. "I don't think people have yet focused on that. We're serious about change. That is my mission."

As the opinion polls do not yet point to a Liberal Democrat government, Mr Brown sensed an opening. "There are two competing visions of the future," he said. "If you want a referendum on the new politics, you have got to consider voting Labour. We are the only party committed to a referendum on it. You won't get one with the Tories.

"We are talking about the political system, not about personalities. You can change the personnel, but you won't change the political system. The Conservatives offer no change. You would get a change of personnel and a return to the old politics."

Mr Brown was interviewed during his train journey to Oxford to visit the BMW Mini plant and launch Labour's "growth manifesto". Yet it is the sudden growth of the Liberal Democrats that is exercising Labour's best minds. While Mr Clegg's rising popularity may be obstructing David Cameron's path to Downing Street, it poses problems for Labour too. Mr Brown knows the public are hungry for change; he cannot allow the election to become a choice of change between Mr Clegg and Mr Cameron. The Prime Minister said: "2010 is about securing the recovery. 2011 will be about entrenching that, ensuring the jobs for the future, and creating a new politics."

The question Labour knows it must answer urgently now is "Why Brown?". His answer is that his "unique selling point" is his experience and judgement and ability to learn from past mistakes – as well as fair policies to meet the new challenges facing Britain.

Had Mr Brown been surprised by the Clegg phenomenon? "I am not surprised by anything," he said with a rather weary smile. He looked a bit tired but his face suddenly lit up when we stopped at a station. I wondered why: a woman with a pink camera was taking his picture through the train window. "Nice to see you," he beamed, no doubt for the thousandth time in this campaign. As the train moved off, he relaxed again and the smile faded.

Mr Brown acknowledged that Mr Clegg had "energised" the debate about the future, saying: "I have always advised people to have a second look at the Conservatives – a long, hard look at them. People are doing that. I think people are going to take a long, hard look at the Liberals as well."

He criticised Mr Clegg's party for "unfair" policies such as cutting Labour's tax credits and child trust funds for newborn babies, noting that the Tories were proposing the same. But he pointed up the shared Lib-Lab agenda on reform. "There is some common ground on the constitutional issues. It is up to the Liberals to respond," he said. "A new politics demands a new House of Commons and new House of Lords. The Conservatives are against a new politics."

Mr Brown added: "The polls are a reflection of an election that is wide open. A few weeks ago the Tories assumed it was a closed book. Now it is wide open. People are looking at all the parties. "Once they turn from presentation to policy issues, people will say, 'Who is the best for the NHS, schools, the police?'

"The Conservative Party is an experiment with do-it-yourself, 'you are on your own' public services, without the guarantees offered by Labour. The 'big society' is about big spending cuts and a big risk."

Surely, Mr Brown would have no mandate to continue as Prime Minister if Labour came third in the popular vote and ended up with the most seats, as several recent polls have suggested? He avoided the question, saying there were "large numbers of undecided voters" and polls were volatile after the credit crunch and the political crisis sparked by the expenses controversy.

Would he stand aside to keep Labour in power if, as some Liberal Democrats suggest privately, he were the obstacle to a Lib-Lab deal in a hung parliament? He scoffed at the idea without killing it. "People are not going to make decisions on issues like that. It is up to the British people to decide," he said. "We are going into the election with a plan, a manifesto for a parliament. We put that to the British people and get their views on it. You would not expect me to speculate on what happens [then]. It is in the people's hands."

The other post-election question is whether Mr Brown will hint that he might stand down during the next parliament to counter the Tory attack line about "another five years of Gordon Brown". On this, the Prime Minister was more definitive. "I am standing on a manifesto for a full parliament," he insisted.

Does his "progressive alliance" mean encouraging anti-Tory tactical voting by Liberal Democrat supporters, as Lord Adonis did in his recent article in The Independent? Mr Brown repeated the Transport Secretary's appeal, saying Labour was also ready to "move forward to the next stage of constitutional reform" such as fixed-term parliaments and possibly a written constitution. But he stopped short of giving a nod and wink to Labour supporters to back the Liberal Democrats in the seats where they go head-to-head with the Tories in the South and South-west of England.

Trying to play down fears in the City of London about a hung parliament, Mr Brown said: "I will do everything in my power to make sure the economic stability we brought back after the financial crisis is maintained."

It seems Mr Brown will not be changing his tactics in the second leaders' debate tomorrow. "I don't know what you mean by tactics," he replied. "I will be me. I will be myself."

Whatever his tactics, he hopes to confound his critics, including the Murdoch-owned newspaper The Sun, which came out for Mr Cameron last October. "It has been so opposed to us for so long that it is seen as the Conservative Party newspaper," he said. "It lost the chance to have a real influence on this election by doing what it did."

Insisting Labour can still win because the climate is so volatile, Mr Brown said: "We are going for a majority. I am a fighter. People have written me off many, many times. I don't think I would be here unless I was prepared to fight for everything I have got. I have not come up the easy way, without it being hard or tough. I have had to endure quite a lot of setbacks. It makes you stronger, tougher and more resilient."