Nigel Farage is facing renewed scrutiny over his ties to the cryptocurrency industry after the Liberal Democrats asked the Financial Conduct Authority to examine whether his promotion of a £2m bitcoin purchase by Stack BTC could amount to market abuse or a conflict of interest.

The complaint follows the release of a promotional video showing the Reform UK leader at the London offices of Blockchain.com helping to publicise Stack BTC’s latest purchase of bitcoin. Stack, a small Aquis-listed “bitcoin treasury” company chaired by former chancellor Kwasi Kwarteng, said it bought 37 bitcoin for about £2m on 13 April, taking its total holdings to 68.1898 bitcoin.

Farage is not only the public face of the transaction. He is also a shareholder in Stack, having built a stake of roughly 5.7 to 6.3 per cent through investments worth about £275,650, according to market disclosures and published reports.

That overlap between political advocacy and personal financial interest has become the centre of the row. Farage has positioned Reform as Britain’s most explicitly pro-crypto party, backing a sovereign bitcoin reserve, lighter tax treatment for cryptoassets and allowing HMRC to accept bitcoin for tax payments.

In a letter to FCA chief executive Nikhil Rathi, Liberal Democrat deputy leader Daisy Cooper said: “No politician should be exploiting their platform to potentially enrich themselves or specific vested interests.” She asked the regulator to investigate whether Farage’s public promotion of Stack and cryptocurrencies could constitute attempted market abuse and whether his holding created a conflict with his role as an MP and party leader.

The FCA has not announced a formal investigation. The regulator has said it will review the letter and respond.

Stack described the transaction as a significant moment for bitcoin in British politics. In the video released on social media, Farage appears to press the button for the purchase before later appearing alongside Kwarteng. The company’s model is unusual even by crypto standards: rather than operating a conventional exchange or payments business, it exists primarily to accumulate bitcoin and to build a listed vehicle whose share price is expected to track the value of its digital asset holdings and related acquisitions.

Farage’s holding in the company has already proved lucrative on paper. He first invested £215,000 through his company, Thorn In The Side Ltd, buying 4.3 million shares at 5p in March. He later subscribed a further £60,650 for 606,500 shares at 10p in a £1.8m fundraising. After his involvement became public, Stack’s share price briefly rose about fourfold, according to previous reporting, before easing back. Even after that pullback, the value of his stake has remained well above his entry price, leaving him with a paper gain of more than £200,000.

Stack has rejected suggestions that Farage was given preferential treatment, saying he invested on the same terms as every other shareholder.

A spokesman for Farage described the event as a “photocall” and said the Reform leader had bought the £2m of crypto on behalf of Stack, not personally. The spokesman added that Farage would do “whatever is appropriate” with his Stack shares if he entered government.

Kwarteng has also defended the arrangement. Speaking this week, he said bitcoin was a roughly $2tn market and argued that “the idea that Farage can influence it is ridiculous”. He said he expected Farage would either put the shares in a blind trust, sell them or recuse himself from crypto-related decisions if he ever entered government.

Kwarteng also argued that Farage’s use of a listed company rather than holding bitcoin directly made his position more transparent. “Everyone who buys shares intends to make some sort of money from them,” he said.

The controversy has drawn attention not just because of the size of the trade, but because it comes amid broader political and regulatory pressure around crypto in Britain. Since October 2023, the FCA’s financial promotions regime has applied to cryptoasset marketing aimed at UK consumers, including content on social media. The rules require promotions to be made or approved by authorised firms or to fall within narrow exemptions, and they are meant to ensure that high-risk investments are presented fairly and with appropriate warnings.

There has been no public allegation that Farage had inside information or that Stack published false information. The issue raised by critics is narrower, but politically sensitive: whether a serving MP and party leader should use his public platform to promote a company and an asset class in which he has a direct financial stake, particularly while campaigning for policies that could favour that market.

Concern about the optics has extended beyond Farage’s opponents on the centre-left. Fraser Nelson, the former editor of the Spectator, described the arrangement last month as “a scandal hiding in plain sight”, arguing that most politicians dispose of shares to avoid even the appearance of a conflict. He has also warned that some investors may come to see Stack not only as a proxy for bitcoin, but as a wager on Farage’s own political rise and on Reform’s crypto agenda.

Stack’s board and backers have their own political and commercial links. The company is chaired by Kwarteng, who briefly served as chancellor under Liz Truss in 2022 and had previously dismissed bitcoin as a “total crapshoot” before later embracing the sector. Stack was co-founded by Paul Withers, owner of Direct Bullion, the gold firm that has already paid Farage about £226,200 for promotional work as a brand ambassador.

The dispute also lands at a moment when Reform’s wider relationship with the crypto industry is under growing examination. Farage has spent the past year building ties with crypto investors and conference organisers, presenting digital assets as part of a broader low-tax, deregulatory agenda. Reform has published a draft Cryptoassets and Digital Finance Bill proposing a 10 per cent capital gains tax rate on crypto, a Bitcoin Reserve Fund within official reserves, a two-year blockchain sandbox and rules designed to stop banks from refusing services to lawful crypto users.

At the same time, the party has taken substantial support from crypto-linked donors. Christopher Harborne, an investor in the stablecoin firm Tether, gave Reform £9m last year and a further £3m this year, according to previous reporting. Ben Delo, the BitMEX co-founder, said last week that he had donated £4m to Reform since the start of 2026. Harborne’s £9m contribution was reported as the largest single donation by a living individual to a UK political party.

Those donations are now part of a wider debate about money, transparency and digital assets in British politics. Last month the government introduced a temporary moratorium on cryptocurrency donations to political parties and capped annual donations from Britons living abroad at £100,000. Ministers said the measures were intended to guard against opaque funding and foreign interference. The Electoral Commission has previously warned that it lacks full powers and visibility to track some crypto-linked donations effectively.

Reaction from within the crypto sector has been mixed. Some executives see Farage’s involvement as a boost for mainstream acceptance. Andrew Webley, chief executive of The Smarter Web Company, a larger London-listed bitcoin treasury business, said it was “clearly a good thing for the sector” to have someone who “might end up as prime minister” taking bitcoin seriously and credited Farage with getting “people talking about bitcoin”.

Others in the bitcoin community have privately expressed unease that one of the country’s most polarising politicians is becoming so closely associated with the asset.

For now, the immediate question is whether the FCA decides the Stack promotion warrants closer examination. What is already clear is that Farage’s £2m bitcoin publicity event has turned a niche listed company into the latest flashpoint in the wider battle over cryptocurrency, political money and conflicts of interest in Westminster.