Here's how much money people have spent trying to force a Brexit

Groups in favour of Britain leaving the European Union - dubbed a Brexit- have given more than £8 million to pro-Brexit campaign groups so far, according to data released by the Electoral Commission on Wednesday.

Between February 1 and April 21, the various leave campaigns - which existed prior to Vote Leave's designation as the official Brexit campaign group - received £8.18 million, more than £700,000 more than the remain campaigners. Remain groups were given £7.46 million.

The biggest individual donation to any campaign was a £3.2 million donation given by the founder and former chairman of investment firm Hargreaves Lansdown, Peter Hargreaves. He made the donation to the Leave.EU campaign, which lost out to Vote Leave as the officially designated campaign in April.

Hargreaves has been one of the most outspoken pro-Brexit business people ahead of the referendum, and in March said that Brexit would be an "inspiration" to the UK's economy.

"I'm firmly convinced, that day -hopefully - we decide to leave, that little bit of insecurity, that little bit of unknown will be an absolute fillip to everyone," he told BBC Radio 4's Today programme.

Along with Hargreaves' donation, another pro-Brexit campaign was the recipient of the second largest donation so far. Grassroots Out - the group backed by the leader of UKIP Nigel Farage and Tory MPs Liam Fox and Peter Bone - was given £1.95 million by an entity called Better For the Country Ltd. Better For the Country is run by Leave.EU head Arron Banks.

On the other side of the campaign, the In Campaign's biggest two donations so far came from former Sainsbury's chairman David Sainsbury, who gave donations of £1.6 million and £750,000.

Here is a selection of some of the other big donations given to either side so far:

• Vote Leave - Patrick Barbour, one of the founders of free-market think-tank Reform, gave £500,000.
• Vote Leave - Peter Cruddas, the founder of derivatives dealer, CMC Markets, handed over £350,000.
• Vote Leave - Tory peer and one of the founders of the Red Kite hedge fund, Michael Farmer gave leave £200,000.
• The In Campaign - £500,000 was donated by a company called The Tower Limited Partnership.
• The In Campaign - Lloyd Dorfman, the founder of Travelex gave £500,000.
• The In Campaign - Businessman and chairman of Winton Capital, David Harding gave £750,000.

You can see the full list of major donors to EU Referendum campaigns - which includes several big banks, and Bloomberg - on the Electoral Commission's website.