The Labour leader set out a series of conditions after judges ruled Prime Minister Mrs May needed parliamentary approval to officially trigger Brexit.
Referring to them as his ‘four bottom lines’, they included access to the single market, no ‘watering down’ of EU workplace rights, a promise from the Government to fund any EU investments lost due to Brexit and a guarantee on safeguarding consumers and the environment.
He suggested his MPs could mount a rebellion and not support invoking Article 50 - the formal process of leaving the EU - if these demands were not met.
The Government lost a High Court battle after judge ruled Mrs May needed parliamentary approval to trigger the two-year process to extricate the UK from the EU. Mrs May's team has launched an appeal with the Supreme Court, amid accusations of betrayal aimed at the judges.
But despite the firebrand lefty inferring he may block Brexit, his deputy Tom Watson quelled the rumours by flat-out denying Labour MPs would stop the UK leaving the EU.
He said: “We're not going to hold this up. The British people have spoken and Article 50 will be triggered when it comes to Westminster.
Praise for Tom Watson? - It may seem a rather odd scenario but it is a no-brainer.
Labour forcing a General Election? - They'd face a near wipeout!