Theresa May will send "shockwaves" around factories and shopfloors and put millions of jobs in jeopardy if she looks to "appease the hard right" with her Brexit plans, the leader of the UK's biggest trade union has said.
Len McCluskey, general secretary of Unite, urged the prime minister not to listen to the "Brexit headbangers" in Cabinet and abandon the single market - the EU trading bloc that demands free movement of people.
Trade unions and others have clearly outlined how real concerns over the freedom of movement can be addressed by sensible labour market safeguards without abandoning the single market when we leave the EU.
Out of the single market, possibly out of the customs union, then investment in core sectors like car manufacturing, chemicals, aerospace, even food manufacturing, will be threatened as companies face hefty on-costs and serious disruption to their supply chains.
TUC general secretary Frances O'Grady said Mrs May must present a plan that ensures "working people don't pay the price" for Brexit amid inevitable market volatility.
Signs that the UK will leave the single market are reducing confidence in the British economy and the falling pound looks likely to keep pushing up prices on everyday goods this year.
The Prime Minister's plan for Brexit today must make sure that wages keep rising, as well as protecting jobs and rights, so that working people don't pay the price for the decision to leave the EU.
Jeremy Corbyn has accused Theresa May of producing a "bargain basement Brexit" plan and "demeaning" the UK's European standing.
Following Theresa May's announcement of her plans for Brexit, how have newspapers across Europe and the UK reacted?
The Prime Minister said Parliament will be given a binding vote on the final deal, but said the result will not stop Britain leaving the EU.