The FTSE 100 and the FTSE 250 plummeted this morning after the Prime Minister signalled Brexit will mean leaving the single market.
Theresa May is expected to rule out “partial membership” or any other kind of “half-in, half-out” deal with the EU in a speech later today.
The FTSE 100, the index of the UK’s 100 biggest companies, and the FTSE 250 both fell more than 0.3 per cent immediately after opening.
The worst performers included the housebuilder Barratt Developments, consumer goods tester Intertek and the mining company BHP.
Stock markets have been buoyant since Brexit, in part because many of Britain’s biggest companies are international and benefit from a devalued pound.
However, while markets fell, the pound crept up against the dollar, to $1.21.
Critics of the Prime Minister say she is sacrificing the economy to prioritise immigration controls.
TUC general secretary Frances O’Grady warned: “If we leave the single market, working people will end up paying the price. It’d be bad for jobs, for work rights & for our living standards.”
According to the Office for National Statistics, inflation rose from 1.2 per cent in November to 1.6 per cent in December.