Theresa May’s election triumph will be wrecked by 'Black Wednesday-style' crisis within months, Tim Farron predicts

'Within a matter of months, she will be in the same sort of mess that John Major and Norman Lamont were in after Black Wednesday,’ says the Lib Dem leader

Tim Farron: 'I’m confident we will be the only opposition party making gains' (PA)

Theresa May will be dragged down by a “Black Wednesday-style” crisis within months of her expected election triumph, Liberal Democrat leader Tim Farron has predicted.

In a close-of-campaign interview, Mr Farron warned the Prime Minister’s joy would be shortlived – because Brexit would overwhelm her, just as a disastrous European policy swamped John Major’s premiership.

In late 1992, public opinion turned sharply against a Conservative Prime Minister, five months after his own election victory, when sterling crashed out of the Exchange Rate Mechanism (ERM).

Later, the Treasury estimated that the unsuccessful fight to keep the pound in the ERM had cost taxpayers £3.4bn – wrecking the Tories’ reputation for economic competence.

In the same way, Mr Farron said, the folly of Ms May’s Brexit policy would quickly be exposed, forecasting an early collapse of the exit negotiations.

“She may win a landslide like Margaret Thatcher but, within a matter of months, she will be in the same sort of mess that John Major and [Chancellor] Norman Lamont were in after Black Wednesday,” he told The Independent.

“Early on, it will become clear that any free trade deal hinges on adjudication by the European Court of Justice – and I can’t see how she has any wriggle room, politically, to deliver that.”

At a campaign event this week, the Prime Minister vowed: “I am very clear that the European Court of Justice and its jurisdiction in the UK is going to be ended.”

Mr Farron said there could be an attempt to fudge the issue, with adjudication by a body linked to the ECJ, but added: “The Tory party would tear itself to bits over that.

“The chances of her getting that past the likes of Dominic Raab and David Davies – let alone the Bill Cashes of this world – are absolutely zero.”

The Lib Dem leader added that business would be “horrified” by the failure, at the same time as the public was recoiling over fresh cuts to schools, the police and health services.

“Already, two-thirds of headteachers are making redundancies – and that’s before it becomes apparent that we are heading, not for a hard Brexit, but for a granite Brexit,” Mr Farron said.

“It’s almost impossible to see how Theresa May doesn’t have the sort of year that, by Christmas, leaves her looking like John Major and Norman Lamont.”

Asked if that meant he believed the UK leaving the EU with “no deal” was now inevitable – which Ms May has said she would accept – Mr Farron replied: “I suspect it is.”

The interview took place as Mr Farron travelled across the Pennines to Yorkshire, at the end of what appears likely to be a hugely disappointing campaign for his party.

Far from gaining large numbers of seats – thanks to angry Remain-backing voters – the Lib Dems are fighting to cling onto the nine they have, marooned in single figures in the polls.

Last week, Mr Farron pointed to his opposition to the “dementia tax” as his “big offer”, apparently downgrading his calling card at the start of the campaign – a second referendum on any final Brexit deal.

But he denied he had switched tack, saying a further referendum, 1p on income tax to rescue the NHS and social care and fighting the dementia tax had always been his “three points throughout the campaign”.

“I’m confident we will be the only opposition party making gains – although, given that both Labour and the SNP will contract, they may not be saying much,” the Lib Dem leader said.

On his own seat of Westmoreland and Lonsdale, Mr Farron said: “I have never taken it for granted – if I had I would deserve to lose – but it’s looking very good, for what it’s worth.”