A senior Tory today branded Reform UK as 'economic fantasists' as he set out why Kemi Badenoch will never do a deal with Nigel Farage's 'toxic' party.

Mel Stride, the shadow chancellor, claimed Reform's 'numbers never add up' as he criticised their 'irresponsible' promises and 'unfunded' spending commitments.

It came after Tory leader Kemi Badenoch killed off any prospect of an electoral pact with Mr Farage after Reform's poor showing in last week's by-elections.

In an article for the Mail on Sunday, Mrs Badenoch emphasised distinctions between her Conservatives and Reform.

She criticised Mr Farage's party over their support for 'a bigger state, more spending, nationalisation, gimmicks and unfunded giveaways', saying: 'Reform dress like Thatcherites but act like Corbynites'.

The Tory leader's comments have dashed any immediate prospect of the main Right-wing parties joining forces to defeat Labour.

Despite Reform's initial hopes of running Labour's Andy Burnham close in the Makerfield by-election on Thursday, he won 55 per cent of the vote - well ahead of Reform's Robert Kenyon on 35 per cent.

On the same day, the Tories won a Westminster by-election in Scotland for the first time in more than 50 years, taking Aberdeen South from the SNP.

Explaining why Mrs Badenoch was ruling out a deal with Reform in the wake of the by-election results, Sir Mel told Sky News on Sunday: 'Reform are economic fantasists - the numbers never add up.

'They had £140 billion worth of unfunded commitments and tax cuts.'

He added of Mr Farage's party: 'The numbers do not add up and, seemingly, they do not seem to care about that.

'They just simply think that if you go out and promise the Earth to everybody, somehow that is going to be enough - well, it isn't responsible.'

There have been suggestions that some Tory voters backed Labour in Makerfield in order to stop Reform.

Mr Farage's party were also squeezed out in the Gorton and Denton by-election in February, as anti-Reform voters flooded to the Greens.

Sir Mel said: 'The second thing is this point about toxicity. Why would we want to get in bed with a party that is going to continuously get hammered by tactical voting?

'An increasingly large proportion of the electorate do not like populist politics.'

The Tories have been stung by a series of high-profile defections to Reform in recent years.

Asked if the Conservatives would now accept disillusioned Reform members wanting to defect the other way or rejoin the Tories, Sir Mel said: 'Well, we'll have to see.

'Look, at the end of the day we are seeing... there was a local councillor, recently who's come back and left Reform and says that he's very sorry they left in the first place and he was sold all sorts of lies about what Reform were.

'He saw them close up and the way that they work in local government, he doesn't want to have anything more to do with it.

'We will see, probably, increasing examples of that, but it will be a case-by-case basis, and it will be for Kemi to make those decisions. Not for me.'

Michael Gove, the Conservative peer and ex-Cabinet minister, said the Tories' victory in Aberdeen South showed Reform's argument that his party are 'irredeemably tainted' by their 14 years in government 'no longer holds'.

'That means it's game on in the fight for disaffected voters between Reform and the Conservatives in a way it wasn't before,' Lord Gove added.

In her article for the Mail on Sunday, Mrs Badenoch said of the differences between the Tories and Reform: 'We are not the same, and voters are not ours to trade like football cards.'

'Farage may be trying to unite the Right, I am trying to unite the country,' she added. 

'Some say refusing a deal risks letting in Left-wing coalitions. I disagree. The way to stop Left-wing coalitions is to build a Conservative majority that reaches beyond the Right.

''Unite the Right' is really just a demand that Conservatives stand down and give Reform a free run because they can't win a general election otherwise. Well, we can.'

A Reform spokesman said Mrs Badenoch's comments about their politics were 'quite ironic - as it's exactly how the Tories governed in office. She was one of the main culprits who dressed like a Thatcherite and acted like a Corbynite'.

The spokesman added: 'We won't need to ever deal with the Tories. They broke Britain and we won't give them a chance to do it again. We have now led the national opinion polls for well over a year.

'Kemi has taken the Tories backwards, from 25 per cent to 18 per cent.'