The Prime Minister will tell business leaders the Tories will put an end to Brexit “uncertainty and confusion” if they are returned to power on December 12.

Boris Johnson made the pledge as he unveiled tax cuts his party said are designed to help companies “make the most of Brexit”.

A Tory Government would cut business rates, launching a fundamental review at their first Budget, under the plans.

The party said they will increase the employment allowance from £3,000 to £4,000, providing a tax cut of up to £1,000 for more than half a million businesses.

The R&D tax credit rate will increase from 12% to 13%, which the Conservatives say will boost manufacturing and the professional, scientific and technical services sectors in particular.

They have also promised to increase the structures and buildings allowance (SBA) from 2% to 3% to increase the tax relief on the purchase, building or leasing of a structure.

In a speech to business leaders at the Confederation of British Industry annual conference on Monday, Mr Johnson is expected to say: “Let’s not beat around the bush, big business didn’t want Brexit.

“You made that clear in 2016 and this body said it louder than any other.

“But what is also clear is that what you want now – and have wanted for some time – is certainty.

“So that you can plan and invest, so you can grow and expand, so that you can create jobs and drive prosperity.”

He is expected to add: “Whilst you didn’t want it, the people did vote for it. And so it was for politicians to deliver it.

“It has been politicians in a broken Parliament – not you – that have failed in this and in some cases actively tried to sabotage the democratic will of the people.

“This is why we had to have this election. Our hung and broken parliament was set on prolonging this delay.

“Britain stuck in gridlock and our economy stuck in first gear. Extension to extension. Marching business up to the top of the hill, only to march them down again.

“And this is Corbyn’s plan at this election – the chaos and division of two more referendums, continued paralysis, continued uncertainty.”

Mr Johnson will tell delegates getting Brexit over the line will allow businesses to get back to doing what they do best.

“With a Conservative majority Government you can be sure we will get Brexit done and leave with the new deal that is already agreed – ending the uncertainty and confusion that has paralysed our economy,” he is expected to say.

“We can then focus on the people’s priorities – investing in the NHS, cutting crime and making sure our children get a world class education.

“And you can focus on what you do best – spurring innovation, creating jobs, stimulating growth.”

The Conservatives said the cumulative benefit to businesses of the changes to the employment allowance, SBA and R&D tax credits will be approximately £1 billion in 2022-23.

Federation of Small Businesses national chairman Mike Cherry, said: “These measures lay down a gauntlet to other parties, and we hope there will be more to come at this election.

“Actions to reduce the cost of employment and fix business rates should be complemented with clear commitments to tackle the scourge of late payments and help ensure the Government is helping the self-employed.

“For example, through introducing a ‘self-employment legislative lock’ and measures to help the self-employed have better access to maternity, paternity and adoption support, and mortgages and pensions.”

Robert Hayton, head of UK business rates at real estate adviser Altus Group, said: “The Government undertook a comprehensive review of business rates at the Budget in March 2015 publishing its response a year later.

“Essentially we will be going over old ground with the tough questions having already been asked albeit that review was fiscally neutral.

“Business, of all sizes, will however be delighted to hear of the commitment to lower the overall burden as we are far too reliant upon property for tax revenues with UK property taxes the highest across the European Union and the standard rate of tax at its highest level since 1990."