Don't lock in Labour for a generation, Rishi Sunak will warn - as the Tories say voters will face 'buyers' remorse if they give Starmer a supermajority

Disaffected Tory voters risk 'locking in a Labour government for a generation' unless they act to prevent a Starmer supermajority, Rishi Sunak will warn on Monday.

The Prime Minister will kick off a final frantic week of campaigning with a direct appeal to 'frustrated' former Tory supporters considering a protest vote on Thursday.

It came after Deputy Prime Minister Oliver Dowden warned 'the bigger the Labour majority, the bigger the buyers' remorse', as he told voters frustrated with the Tory record: 'Don't think about the anger just now.'

In a speech on Monday, Mr Sunak will say voters have 'four days to save Britain from a Labour government which would hike taxes by more than £2,000 for every working family, would shunt our politics to the Left and change the rules to ensure that they can stay in power for decades'. 

He will warn that if Labour gains a supermajority, the party will 'set about entrenching themselves in power' by changing the electoral system, starting with lowering the voting age to 16.

And he will caution that an 'unchecked' Labour government would be 'a disaster from which it would take decades to recover'. 

Opinion polls show growing public concern about the prospect of a landslide Labour victory.

But Tory strategists fear many disaffected Conservative voters consider the outcome is a foregone conclusion and may stay at home or cast a protest vote for Reform, making a victory for Sir Keir Starmer even more likely.

Mr Sunak will acknowledge the 'frustration' felt by voters over a Tory administration knocked off course by the pandemic, the war in Ukraine and party infighting.

But he will warn that failure to back the Conservatives could mean surrendering their voice 'for a generation'.

'This coming week everyone has a big choice to make – and it's a choice not just about how you feel now but what you want the future be,' he will say. 'Do you want your taxes cut or taxes raised? Your pensions protected or pensions raided? Lower immigration or higher immigration? A more secure Britain with more defence spending or lower defence spending?

'You have a voice in this election, don't surrender your voice.'

The latest election mega-poll yesterday predicted that divisions on the Right could hand Sir Keir the biggest majority in British history with a smaller share of the vote than was achieved by Jeremy Corbyn when he lost the 2017 election.

The J L Partners poll predicted that Labour would win 450 seats with just 38 per cent of the vote, while the Conservatives would be reduced to a rump of only 105 seats with 22 per cent of the vote. Reform could get 17 per cent of the vote, but end up with only two seats.

However the poll also showed there are 77 marginal constituencies where the Tories are in second place, meaning that even a small shift in public sentiment could prevent them suffering total wipeout. As the final days of campaigning got under way: 

• Mr Sunak said it was 'clear' that the Kremlin wants him to lose the election, as the Cabinet Office prepared to probe claims that Russia is trying to boost support for Reform;

• Foreign Secretary Lord Cameron branded Sir Keir 'hopelessly naive' as he condemned Labour's failure to match Tory plans to boost defence spending;

• Labour vowed to loosen controls on Britain's green belt within days of taking office in order to boost housebuilding;

• The party's health spokesman, Wes Streeting, indicated he would throw money at striking junior doctors, saying that 'movement on pay' was essential to resolving the long-running dispute;

• Mr Sunak claimed that Labour's plans to cut a new deal with the EU would 'reverse Brexit' and lead to restoration of 'some form of free movement';

• Half of Labour's 2019 voters said they were in favour of the Conservatives' plan to protect single-sex services;

• Sir Keir said Labour would 'relight the fire' of optimism. The main party leaders will spend the next few days criss-crossing the country in a final appeal for votes.

Mr Sunak yesterday insisted he could still win, despite failing to dent Labour's lead during a six-week campaign, but many Tory strategists are now focused on ensuring that the Conservative Party remains a viable fighting force at Westminster.

Business Secretary Kemi Badenoch, tipped as a future Tory leader, suggested that the party will need to move to the Right after the election to win back supporters who have defected to Reform.

But she appealed to disaffected voters to return to the Conservative fold this week to prevent Sir Keir winning unchecked power.

In his speech today, Mr Sunak will focus on the risk that Labour could 'set about entrenching themselves in power' if they win by a landslide.

'Once you have handed Keir Starmer and Labour a blank cheque, you won't be able to get it back,' he will say. 'They will rewrite the rules to make it easier for them to stay in office and harder for anyone to replace them.'

The PM will criticise Labour's plans to give 16-year-olds the vote 'not because they think they are adults, but because they think they will vote for them'.

And he will warn that Sir Keir could revive a previous pledge to give EU citizens the vote and introduce 'a whole new voting system designed to allow politicians to stitch things up behind closed doors and shut you out'.

He will add: 'Don't let them do that. Don't take that risk. Don't surrender to Labour.'

Mr Sunak also defended the Conservatives' record in government against what he described as a 'declinist narrative'. 'It's entirely wrong, this kind of declinist narrative that people have of the UK I wholeheartedly reject,' he told the BBC's Sunday With Laura Kuenssberg programme.

'It [the UK] is a better place to live than it was in 2010.'

Asked whether he thought he would still be in Downing Street after the Election, Mr Sunak said: 'Yes. I'm fighting very hard and I think people are waking up to the real danger of what a Labour government means.'

Meanwhile, Sir Keir spent much of yesterday finalising his plans for Labour's first days in power. 

The Labour leader vowed to 'hit the ground running' if his party returns to power for the first time in 14 years.

Parliament's summer recess will be delayed by a fortnight to give Labour time to relax planning rules and launch a council-led review of the green belt. 

He is also planning to appoint dozens of new peers to prevent the House of Lords blocking Labour's agenda.