The controversial Leave.EU co-founder Arron Banks, who was barred from joining the Conservative party, gave a cash donation to a Tory MP’s general election campaign, it has been revealed. Brexiter Andrea Jenkyns has defended receiving money from the businessman in November, weeks before she held her seat of Morley and Outwood in West Yorkshire.

It is the first time that the insurance entrepreneur has made a political donation since Leave.EU was found to have broken electoral law in 2018. That year, Banks was prevented from joining the Tories after urging hardline Brexiters to flood the party to depose the then prime minister, Theresa May.

Banks has consistently denied claims that he received money from Russia, but the source of his wealth has been under scrutiny since he gave £9m to Leave.EU, the largest political donation in British history.

Speaking from New Zealand, Banks told the Guardian that the donation of £2,000 to Jenkyns’ office was a reflection of a thawing of relationships between Leave.EU and the Conservative party since Boris Johnson took over the party.

“We are much friendlier with the Conservative party,” he said. “We supported them during the campaign and so we have a fairly cordial relationship. Boris is doing a great job. I have just been watching President Trump’s State of the Union address, so I think I can say that Boris is making Britain great again.”

Jenkyns received his donation, he said, because of her close links with Leave.EU. She has also featured on Westmonster, the website he helped to bankroll.

“Andrea has been a big supporter of Leave.EU and I supposed I thought it would be good to offer my personal support,” he said.

Banks said he was not aware of any checks by the Conservative party about whether he was allowed to give money, given that he was barred from joining the party in 2018.

Jenkyns, whose majority increased from 2,104 to 11,267, defended receiving the money. “This was a personal donation to my re-election campaign. All donations to my campaign have been properly and transparently declared in the usual way,” she said.

Banks emerged on to the political scene in 2014 when, having been a Tory donor, he publicly defected to Ukip, led by Nigel Farage. Since then, he has handed millions to political parties and organisations campaigning to leave the EU. Questions were raised about the whether Leave.EU broke electoral spending rules.

The Electoral Commission concluded in May 2018 that Leave.EU had committed multiple breaches of electoral spending law during the EU referendum and fined it £70,000, saying the “unlawful overspend” was at least £77,380 but may well have been higher.

The commission also found that Leave.EU inaccurately reported three loans it had received from companies controlled by Banks.

However, the commission found no evidence that Leave.EU received donations or paid-for services from Cambridge Analytica for its referendum campaigning and found that the relationship with the political campaign agency “did not develop beyond initial scoping work”.

Banks responded by accusing the commission of a “politically motivated attack on Brexit” and threatened to take legal action.

The Metropolitan police announced in September that it would be taking no further action against Leave.EU for spending offences in the Brexit referendum, despite accepting that it had broken the law.

Farage claimed in April that Banks would not be handing over political donations in future because he had been “badly burned” by repeated questions over the £9m he contributed to the Brexit campaign.

On Wednesday, Banks said he would consider making further donations and claimed that he was still pursuing legal action against the commission that would challenge its previous ruling..

“We have issued against the Electoral Commission and are talking about whether to settle or not. The police exonerated us. We are keen to see why they [the commission] did what they did.”

Banks confirmed that he was still pursuing legal action against the investigative journalist Carole Cadwalladr, despite dropping two elements of his libel claim in January.

Cadwalladr has won a series of prestigious journalism prizes for her work, published in the Guardian and Observer, exposing the Cambridge Analytica data-harvesting scandal and spending by pro-Brexit campaigners in the EU referendum.

Ben Bradshaw, the Labour MP who has previously called for an inquiry into Banks’s links to Russia, said: “It is no surprise that the man who broke electoral law but against whom the government took no action has since decided to help prop the Tories up.”

The National Crime Agency previously said it found no evidence Leave.EU and Banks broke the law. The Conservative party has been approached for a comment.