The fundraising structure adopted by the Brexit party leaves it at risk of receiving impermissible donations, the Electoral Commission warned today.
The UK regulator said the party, which was established by Nigel Farage following his resignation from UKIP last year, was using an online system to receive donations which could be open to abuse.
The Electoral Commission visited the Brexit party's London offices last month to review the systems it had in place to receive funds.
It concluded the fundraising structure adopted by the party leaves it open to "a high and on-going risk of receiving and accepting impermissible donations".
The commission has since made recommendations that it said would, if implemented by the party, achieve and maintain robust procedures for receiving funds and help it comply with its legal requirements.
READ MORE: Farage visits Downing Street to demand role in Brexit talks
Louise Edwards, director of regulation at the Electoral Commission, said: “It is legitimate for any political party or campaigner to adopt a fundraising strategy that focuses on raising small sums.
"Our visit to The Brexit Party has enabled us to make specific recommendations to the party that will support it to meet its legal responsibilities when it comes to receiving funds. Should it fail to meet those responsibilities, this will be considered in line with our Enforcement Policy.”
The Brexit party was the success story of last month's elections to the European Parliament, where it returned 29 of the UK's 73 MEPs.
Last week, Mr Farage handed a letter to Downing Street to demand involvement in the Brexit negotiation process.
The letter, addressed to the Prime Minister and copied to all the Conservative leadership candidates, reads: “The electorate have asked for us to come into the negotiating team and we are ready to do so immediately.”
But the party faced a set-back when it failed to win the Peterborough by-election, which would have seen it return an MP for the first time.
When asked about losing the by-election in which his party’s candidate came a close second to Labour, Mr Farage said: “Did we? I don’t know, if you think zero to 29 per cent in a couple of weeks is losing, then it’s losing.”