The former chancellor Philip Hammond has added another job to the dozen or so he has taken on since leaving the Treasury in 2019, this time as an adviser to a Mayfair-based cryptocurrency trading firm. Lord Hammond, who also served as foreign secretary and was an early supporter of bitcoin and other digital currencies, joined Copper.co with immediate effect on Monday. The former chancellor, who was said to be one of the wealthiest ever cabinet ministers with a fortune once estimated at £8.2m, has taken up as many as 14 paid and unpaid jobs since leaving politics after a bust-up with Boris Johnson over Brexit. Hammond was last month criticised by Westminster’s lobbying watchdog for using his government connections to assist OakNorth, a bank he is paid to advise. Eric Pickles, a former cabinet colleague who chairs the Advisory Committee on Business Appointments (Acoba), said it was an unwise step for Hammond to contact a senior Treasury official about a project developed by OakNorth. Lord Pickles said Hammond’s use of his contacts in government was not consistent with the intention of the rules and was not acceptable because of “the privileged access you obtained for OakNorth”. Hammond, who also served as defence secretary, was later cleared of breaching lobbying rules after an investigation by the Office of the Registrar of Consultant Lobbyists (ORCL), an independent body that monitors lobbying activities of former ministers and senior civil servants. ORCL accepted Hammond’s argument that, since lobbying was not his main activity, there was no need for him to register as a lobbyist working on behalf of a third party. Copper said Hammond would focus on “promoting the UK as a global leader in digital asset technology”. The firm, which was founded in 2018, recently announced plans to expand into the US and Asia and secured $75m (£55m) of investment from the British billionaire hedge fund manager Alan Howard and the venture capital firms Dawn Capital and Target Global. Hammond said Copper was a “true pioneer” of crypto and digital asset investment technology. “But the really exciting opportunity lies in the application of this technology to revolutionise the way financial services are delivered,” he said. “If we can bring together the best of Britain – entrepreneurs, industry, government, and regulators – to create and enable a blockchain-based ecosystem for financial services, we will secure the UK’s global leadership in this field for decades ahead.” Dmitry Tokarev, the chief executive of Copper, said: “We would like to drive growth in our client base within a regulatory framework which will allow us to thrive globally from our London headquarters. With Lord Hammond’s expertise adding to the strength of our team, we look forward to growing Copper and further enhancing the UK’s digital asset technology offering.” As chancellor, Hammond had called for light-touch regulations for cryptocurrencies. “I am interested in bitcoin. The Bank of England, as you know, among the central banks, has been leading on looking at bitcoin,” he said in 2018. “What is really important is that in regulating cryptocurrencies, we don’t inadvertently constrain the potential of the technology that underlies it, the blockchain technology, which has a wider and more important application.”