THERESA May has been accused by Labour of "utter hypocrisy" after it emerged that she voted against the implementation of the referendum approving the creation of the Welsh Assembly.

The SNP made the same charge, saying the Prime Minister had backed a wrecking amendment to the 1998 Scotland Bill.

In a keynote speech today in Stoke-on-Trent, which voted heavily to leave the EU, Mrs May once again urged her colleagues to back her Brexit Plan, warning that to reject it could lead to a no-deal outcome or the "more likely outcome is a paralysis in Parliament that risks there‪‪ being no Brexit".

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But she also used her address to underline the importance of implementing the will of the people as expressed in referendums.

The PM noted how the result of the Welsh referendum of 1997 was "accepted by both sides" despite being carried by a wafer-thin 0.3 per cent majority and stressed that every referendum result in the UK had been honoured.

However, parliamentary records show that Mrs May was among 144 MPs who voted for an amendment which would have blocked the Government of Wales Bill giving effect to the Welsh referendum result.

Also backing the amendment were prominent Brexiteers Liam Fox, John Redwood, Iain Duncan Smith, Owen Paterson, Bernard Jenkin and John Whittingdale.

In 2005, the PM stood in the General Election under a Conservative manifesto promising a second referendum to decide whether to overturn the 1997 result.

In her speech, she said: "On the rare occasions when Parliament puts a question to the British people directly we have always understood that their response carries a profound significance.

"When the people of Wales voted by a margin of 0.3 per cent, on a turnout of just over 50 per cent, to endorse the creation of the Welsh Assembly, that result was accepted by Parliament.

"Indeed we have never had a referendum in the United Kingdom that we have not honoured the result of," declared Mrs May.

She went on: "Parliament understood this fact when it voted overwhelmingly to trigger Article 50. And both major parties did so too when they stood on election manifestos in 2017 that pledged to honour the result of the referendum.

"Yet, as we have seen over the last few weeks, there are some in Westminster who would wish to delay or even stop Brexit and who will use every device available to them to do so.

"I ask them to consider the consequences of their actions on the faith of the British people in our democracy.

"The House of Commons did not say to the people of Scotland or Wales that despite voting in favour of a devolved legislature, Parliament knew better and would over-rule them. Or else force them to vote again.

"What if we found ourselves in a situation where Parliament tried to take the UK out of the EU in opposition to a Remain vote? People’s faith in the democratic process and their politicians would suffer catastrophic harm.

"We all have a duty to implement the result of the referendum," insisted Mrs May.

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But the 2005 Conservative manifesto made clear that the party did suggest that the people of Wales should vote again, stating: "In Wales, we will work with the Assembly and give the Welsh people a referendum on whether to keep the Assembly in its current form, increase its powers or abolish it."

Labour MP for Cardiff Central Jo Stevens said the development had exposed "yet more utter hypocrisy from the PM, who, with other leading Brexit Tories, voted against legislation giving effect to the result of the Welsh referendum before it was implemented".

And Cardiff South & Penarth MP Stephen Doughty, a leading supporter of the Best for Britain campaign for a second referendum, said: "This is a very strange example for the PM to use - not least given she herself voted against implementing the Welsh referendum result, and the Tories continued to oppose it for years afterwards.

"But unlike Brexit - the Welsh Assembly grew in public support after the referendum. Brexit has headed decisively in the opposite direction - which is why the people should have the final say."

Meanwhile, Joan McAlpine the SNP MSP also took the PM to task, saying: “Theresa May is increasingly desperate; it seems she’ll now say absolutely anything, no matter how untrue, to try and force MPs to vote for her deal.

“This speech is brazen hypocrisy with Theresa May herself previously voting against a referendum result and then standing on a manifesto that sought a second referendum to overturn it.

“The Tories now think they can do anything they want to Scotland and get away with it. They campaigned tooth and nail to stop devolution in the first place, have launched a power-grab on the Scottish Parliament and are now doing everything they can to drag Scotland out of the EU against our will,” she added.

Before her speech, Mrs May's spokesman said he was sure that when she gave it, "it will be clear in regard to these matters".

In 1997, Wales voted for the creation of a devolved assembly by a margin of 559,419 to 552,698 - 50.3 per cent to 49.7 per cent. The Assembly was brought into being in 1999.

In Scotland, the pro-devolution vote was much more emphatic. The margin was 1,775,045 votes for and 614,400 against – 74.3 per cent to 25.7 per cent.