Richard Branson is bankrolling a campaign to oust MPs who support Brexit, the Mail can reveal.

The Virgin boss, who left Britain four years ago to live offshore, has donated tens of thousands of pounds to the plot to influence the election.

Gina Miller, the millionaire businesswoman who took the Government to court over Brexit, yesterday promised ‘the biggest tactical voting effort in our history’ as she launched the Best for Britain campaign.

Campaigner Gina Miller launched her Best for Britain campaign to attempt to intervene in up to 100 marginal seats, where tactical voting could return an MP open to Britain's future in the EU

The Best for Britain initiative has won £25,000 launch funding from Sir Richard Branson, above, as well as office space

More than £300,000 will be poured into up to 100 marginal seats to help elect candidates who do not rule out the country remaining in the EU.

Mrs Miller said people need to vote tactically in the General Election to avoid an ‘elected dictatorship’ as she claimed nearly 10,000 people had given money to the ‘grassroots movement’.

But today the Mail can reveal the project has been set up in office space provided by Sir Richard and that the businessman given £25,000 to help it launch.

He has also deployed his key lieutenant, Virgin chairman Peter Norris, to help lead the effort as a board member.

Mrs Miller said she wanted to help elect MPs who were prepared to help block Brexit depending on the deal agreed with Brussels.

‘If we have, at the end of the day, if you like, an elected dictatorship, then that’s not democracy,’ she said.

As well as the cash and space, Mr Branson, left, has deployed his key lieutenant, Virgin chairman Peter Norris, to help lead the effort as a board member. Mrs Miller, right, has been known for her work taking the government to court over the way Article 50 is invoked

‘The election was more about power grabbing than strengthening the negotiating hand.’

Mrs Miller, who ruled out standing herself, added: ‘Only tactical voting in this election can ensure that Parliament plays its full role in the future of our country. We need MPs to be strong and open minded about what is best for Britain.

‘The idea that Parliament should simply rubber stamp a binary deal or no deal option put by a future government, and ignore any other alternative, would reduce democracy to a mere footnote.

‘Whilst Brexit is a very important issue in this election, there is a much wider issue here which is about electing MPs who will stand on their principles and hold the government to account.’

Mrs Miller said the Best For Britain group would use its funds to locally support candidates from any party committed to keeping the UK’s Brexit options open.

The campaign said it was still ‘analysing data and algorithms’, but could intervene in up to 100 marginal seats.

Mrs Miller achieved fame last year by bringing a successful High Court action which forced the Government to put its plan to trigger Article 50, marking the start of the formal Brexit process, to a vote of Parliament - a ruling that was upheld by the Supreme Court.

Mrs Miller said the Best For Britain group would use its funds to locally support candidates from any party committed to keeping the UK’s Brexit options open

Mrs Miller has said she will not stand herself, following speculation she would stand in a seat for the next parliament

In 2013, it was revealed that Sir Richard, who is worth £4.5billion, had left Britain to live full time on his private Necker Island in the British Virgin Islands.

He previously lived in a 200-acre Oxfordshire estate and a mansion in Holland Park, West London.

He has said he is too wealthy to allow tax considerations to dictate where he should live.

Following the referendum Sir Richard claimed the Brexit decision had led to the cancellation of a ‘very big deal’ for his company costing 3,000 jobs.

He said: ‘Businesses will suffer and soon the British people will see the costs of goods going up and job losses and they will start to realises the consequences of what they have done,’ he has argued.

‘The referendum was just an advisory referendum. Once people see the terms and the consequences of what’s happening, things could change.’

The launch of Best for Britain comes after Open Britain, the remnants of the official Remain campaign, launched a similar tactical voting drive earlier this week.

A Virgin spokesman last night confirmed the donations but refused to comment further.