Boris Johnson has pledged to cut taxes for hardworking families, change the law on releasing serious offenders halfway through a prison sentence and boost funding for schools within the first 100 days of government if he is re-elected.

The Conservative Party’s plan has been branded “pure fantasy” and the prime minister has been accused of lying to the public, with the Liberal Democrats saying that a Tory government would “remain completely consumed by Brexit not just for the next 100 days, but for years to come”.

The prime minister, however, said 2020 will be “the year we finally put behind us the arguments and uncertainty over Brexit” if the Tories get a majority at the general election.

A Conservative government would announce its legislative programme on 19 December in a new Queen’s Speech, the party said, adding that they will bring back the EU Withdrawal Act Bill before Christmas with all Conservative MPs backing the legislation.

Before 100 days have passed, the Conservatives said they will have delivered a “post-Brexit budget” in February which will cut taxes for hardworking families.

The Tories have promised to raise the threshold for national insurance contributions to £9,500, with the "ultimate ambition" to increase it to £12,500, which would "put almost £500 per year in people's pockets", according to the party's manifesto.

Top 10 marginal seats to watch at the general election Show all 10 1 /10 Top 10 marginal seats to watch at the general election Top 10 marginal seats to watch at the general election North East Fife Currently held by the SNP with a majority of 2 Getty Top 10 marginal seats to watch at the general election Kensington Currently held by Labour with a majority of 20 Getty Top 10 marginal seats to watch at the general election Perth and North Perthshire Currently held by the SNP with a majority of 21 Getty Top 10 marginal seats to watch at the general election Dudley North Currently held by independent, formerly Labour, MP Ian Austin with a majority of 22 LivingInMediocrity Top 10 marginal seats to watch at the general election Newcastle-under-Lyme Currently held by Labour with a majority of 30 Derek Harper Top 10 marginal seats to watch at the general election Southampton Itchen Currently held by the Conservatives with a majority of 31 Rob Candish Top 10 marginal seats to watch at the general election Richmond Park Currently held by the Conservatives with a majority of 45 Robin Webster Top 10 marginal seats to watch at the general election Crewe and Nantwich Currently held by Labour with a majority of 48 Jaggery Top 10 marginal seats to watch at the general election Glasgow South West Currently held by the SNP with a majority of 60 Alec MacKinnon Top 10 marginal seats to watch at the general election Glasgow East Currently held by the SNP with a majority of 75 Christine Johnstone

In the same time frame, the party said they will change the law to end the automatic release of serious violent and sexual offenders at the halfway point, and launch a review of defence, security and foreign policy.

They say they will also legislate for a funding boost for schools, change the law to increase the amount that migrants pay to use the NHS, begin cross-party talks to find a solution to the challenge of social care, and finalise an agreement with mobile phone operators to improve mobile service in the countryside.

The party also said they will have introduced legislation to ensure the extra £33.9bn per year they say they are putting into the NHS by 2023 is enshrined in law, legislation to create a new Australian-style points-based immigration system, and legislation for tougher sentences to ensure terrorists spend longer in prison.

The Conservatives said a Boris Johnson government will have passed the Withdrawal Agreement and delivered Brexit by 22 March.

Mr Johnson said: “We will get Parliament working on the people’s priorities – delivering 50,000 more nurses and 20,000 more police, creating millions more GP appointments, and taking urgent action on the cost of living.

“But if the Conservatives don’t get a majority, then on 13 Friday we will have the nightmare of a hung parliament with Jeremy Corbyn as prime minister propped up by Nicola Sturgeon’s SNP.

“Next year will be Groundhog Day in parliament with MPs arguing every day about the referendum and businesses and families left in limbo, unable to plan their futures.”

Liberal Democrat deputy leader Sir Ed Davey claimed Mr Johnson was “once again lying to the British public by pretending he can actually deliver on any of these promises”.

Support free-thinking journalism and attend Independent events

He added: “This is pure fantasy. We must prevent Johnson getting a blank cheque to crash Britain out of the EU by the end of 2020.”

Andrew Gwynne, Labour’s shadow secretary of state for communities and local government, said: “The Tories have had 3,494 days in office, and in those days we’ve seen child poverty soar, rising homelessness, rising food bank use, and violent crime is up too. The NHS has more people waiting for operations, and record staff vacancies.

“As the Conservatives approach 3,500 days of failure, it’s clear that more of the same failed austerity, privatisation and tax giveaways for the few is not the answer.”