Mr Mittal is also a former Labour donor, having given the party more than £5m when it was under the leadership of Tony Blair and Gordon Brown. He also owns a stake in London football club Queen’s Park Rangers, and his family has donated millions of pounds to good causes.
It first emerged that Mr Mittal was planning to leave Britain in March this year, ahead of Labour’s end to the non-dom regime. Under the previous regime, residents with non-domiciled tax status could avoid paying British tax on foreign income and capital gains.
Earlier this year, Mr Mittal bought a Baroque-style mansion in Dubai’s Emirates Hills, a gated community dubbed the “Beverly Hills of the Middle East” for a reported $200m (£153m).
He has also started buying up tracts of land on the Naïa Island development, which is currently being built off the United Arab Emirates’ coast.
His departure will be embarrassing for the Government on the eve of the Chancellor’s Budget. Ms Reeves is expected to announce a raft of tax rises to balance the books but has insisted she wants to do more to boost Britain’s stagnating economy.
Mr Mittal’s exit is the latest in a string of high-profile departures that have included Nik Storonsky, the founder of Revolut, and Herman Narula, the £2.5bn tech chief executive.
Labour has been criticised over its erratic policy-making in the run-up to the Budget. Ms Reeves had been rumoured to be weighing up an exit tax which would charge 20pc on the gains of wealthy individuals if they chose to leave the country, but dropped the plans over fears it would cause an exodus of millionaires.
A spokesman for ArcelorMittal declined to comment.
