Rishi Sunak to warn there are just 10 days left to stop 'disaster' of a Keir Starmer supermajority as election day approaches

Voters have just ten days to save Britain from the 'disaster' of a Labour supermajority, the Prime Minister will warn on Monday.

In a dramatic message, Rishi Sunak will urge disaffected Tory supporters not to hand 'unchecked' power to Sir Keir Starmer when they cast their ballots on July 4.

He will also call on them to 'think what a Labour government would mean' if they risk a protest vote for Reform. Addressing Tory activists on Monday, the PM will say: 'We have ten days to take our message to every corner of the United Kingdom.

'To make the argument that this country needs lower taxes, not £2,000 more taxes for every working family. To make the case that a Labour government would be bad for our country, and an unchecked Labour government would be a disaster from which it would take decades to recover.'

Mr Sunak will acknowledge public anger with the Tories but insist that the election 'is not a referendum on the Conservative party or me, but a choice – who do you want to be the next government?' 

He will add: 'Before you make that choice, think what a Labour government would mean.'

Pointing to Sir Keir's opaque plans and broken promises he will warn the country risks giving Sir Keir a 'blank cheque'.

He will add: 'When a politician won't tell you what they are going to do, it means that they know you won't like it.

'All their evasions tell you is that they are going to whack up council tax and a bunch of other taxes. And one thing we know about Keir Starmer is that he has no problem going back on his promises. His career is a story of commitments dropped as soon as they became too difficult to keep.

'I tell you this: once you have handed Keir Starmer and Labour a blank cheque, you won't be able to get it back.'

The PM's stark message reflects growing alarm among Tory strategists that disgruntled Conservative voters could accidentally hand Labour a landslide victory by voting for Reform.

Three mega-polls last week suggested that the split on the Right is set to give Sir Keir a Tony Blair-style supermajority.

But analysis of the polling by the Mail suggests that voters in dozens of seats could avert this if they hold their noses and return to the Tory fold.

It came as:

• Boris Johnson accused Nigel Farage of being 'morally repugnant' in his comments about Vladimir Putin; 
• Kemi Badenoch warned that Sir Keir will 'unpick Brexit' if he wins power; 
• Labour's education spokesman Bridget Phillipson suggested the party will scrap guidance banning pupils from being taught that they can change gender; 
• The giant Unite union said it was time for Labour to ditch the 'straitjacket' of spending control; 
• A fourth senior Tory official was accused of placing dozens of bets on the timing of the General Election; 
• Analysis showed Labour's green energy plans would require land the size of Greater London to be covered in wind turbines.

Tory morale has hit rock bottom after a series of campaign setbacks and Mr Sunak's failure to budge Labour's 20-point poll lead. In his speech on Monday, the PM will tell activists they must not 'surrender' – and point out there are many voters for whom 'only we Conservatives will stand up for them and make sure that their voice is heard, their values represented'.

He will say: 'Don't surrender to Labour. Fight for every vote, fight for our values, fight for our vision of Britain.'

Yesterday former immigration minister Robert Jenrick warned that Tory voters flirting with Reform could inadvertently hand Sir Keir a 'supermajority' and allow him to tear up border controls. 

He told Sky News: 'I want to deliver this warning to all of those small-c conservatives across the country... that if they vote for Reform they are going to usher in, I believe, not just a couple of years of harmful Labour government, but potentially a generation of hard-Left Labour rule.'

Writing in the Mail on Monday, Business Secretary Ms Badenoch also warns Brexit supporters risk having the project undone if they vote for Reform.

And former chancellor Philip Hammond warned that it is vital to maintain a healthy Tory opposition if Labour wins. 

He told the BBC that if the party gets 'dragged inexorably to the Left... we need a strong opposition in Parliament to make sure we hold this Labour government – if that's what we get – to account'.

But former Labour business secretary Lord Mandelson dismissed the 'pseudo-scientific' mega-polls, saying: 'I don't believe these polls for one moment. The fact is many people are uncertain.

'Some are undecided, some are doubtful, others are leaning one way or another but haven't finally made up their minds.

'That is why the polls are dangerous – they generate, if you are not careful, a sense of complacency that it is all in the bag. It isn't. If people want change they are going to have to go out and vote for it.'