OWEN Smith has pledged to try to block Theresa May triggering the formal Brexit negotiations until the Prime Minister offers a second referendum or calls a general election to approve the final deal to leave the European Union.

The former shadow work and pensions secretary said that under his leadership Labour would vote against triggering Article 50 of the Lisbon Treaty, that begins the two-year Brexit process, until the Conservatives committed to a second public vote.

Outlining his position exactly two months after the outcome of the historic vote, Mr Smith – who takes on Jeremy Corbyn in a hustings event in Glasgow tomorrow night – warned: "Labour won't give the Tories a blank cheque."

Read more: No economic safety left in the Union after Brexit, claims Sturgeon

He hit out at the “deeply irresponsible” comments made by Mr Corbyn on the morning of the EU referendum result calling for Article 50 to be invoked immediately. The Labour leader has since backtracked and insisted he misspoke.

"The British people were lied to by the Leave campaign; they deserve to have a say on whatever exit deal the Tories strike with the EU,” declared the Pontypridd MP.

"Theresa May says that 'Brexit means Brexit' but nobody knows what Brexit looks like. It could involve trashing workers' rights and environmental protections, opening our NHS up to foreign competition, making it harder for us to trade with our neighbours and damaging our economy."

He added: "I'm a passionate pro-European and I will fight tooth and nail to keep us in the EU.

"Under my leadership, Labour won't give the Tories a blank cheque. We will vote in Parliament to block any attempt to invoke Article 50 until Theresa May commits to a second referendum or a general election on whatever EU exit deal emerges at the end of the process. I hope Jeremy will support me in such a move."

Read more: No economic safety left in the Union after Brexit, claims Sturgeon

Mr Smith has said he has sympathy with Nicola Sturgeon’s bid to keep Scotland within the EU and promised, if he won the Labour crown, to campaign alongside her to keep the whole UK in the Brussels bloc.

But Sir Patrick McLoughlin, the Tory chairman, stressed the result of the June 23 referendum was clear and decisive and the UK Government would deliver on the people's verdict.

"Labour didn't want a referendum and now they want to ignore the outcome. If Labour cannot trust the public, then no one should put their trust in Labour. Whether it's Jeremy Corbyn or Owen Smith, Labour are too divided and out of touch to make a success of Brexit," he added.

Meantime, a quarterly report has found half of working-age households are worried about the impact of Brexit on their financial wellbeing.

Research from savings and Isa provider Scottish Friendly found that 51.9 per cent of British families were concerned about the long-term impact of leaving the EU compared with 48.1 per cent in the last quarter.

Read more: No economic safety left in the Union after Brexit, claims Sturgeon

The Disposable Income Index report, compiled in conjunction with the Social Market Foundation think-tank, showed disposable income remained relatively flat with a small 2.4 per cent improvement overall, bolstered by low inflation and the continued positive impact of the National Living Wage.

However, just 18.8 per cent of households felt they had more cash left over at the end of the month than they did 12 months ago while 47 per cent were worried about how they would deal with a large, unexpected bill.