Jeremy Corbyn has revealed Labour will seek an official amendment to any Article 50 legislation, if Theresa May is forced to seek approval to trigger the mechanism in the Commons.

His comments come as Government lawyers prepare to present their case at the Supreme Court on Monday to trigger Article 50 – the untested protocol for a member state leaving the EU – without an Act of Parliament. Some ministers are privately expecting Downing Street to lose the challenge.

Speaking to Sky News after a speech to the party of European Socialists in Prague, the Labour leader said: “When the Article 50 debate comes up we will put forward an amendment to it, which will be on the issues I’ve just said about market access and protections.”

But the Labour leader reiterated his party would not seek to overturn the decision by the British people to leave the EU at the referendum in June. “We want those to be part of the negotiations but we are respecting the result of the referendum,” he said. ”It’s not the one we wanted – it’s the one we’ve got.”

Mr Corbyn, who is attempting to ensure Britain maintains access to Europe’s markets, workers’ rights and environmental protection measures, added: “You can't say to be people: ‘You vote, you take the decision. Sorry, you’ve made the wrong decision. You’ve got to take it again’.

What is Article 50?

“Two thirds of Labour voters voted to remain. There isn’t a blank cheque to the Government – it’s up to us, to Parliament, to hold the Government to account. That is exactly what we are doing.

“Article 50 will still be invoked. We are not going to block it. We don’t think that's right to do that. But I do think there will be a considerable body of MPs on both sides which does require an amendment that supports a trade agreement with Europe in the future.”

In the event of the Prime Minister losing the Supreme Court case in January, it has been reported the Government is already in the process of drafting a bill in just two or three lines – in an attempt to make it difficult for amendments to succeed.

Mr Corbyn added: “There are those in the Tory party who want us to sever all connection with Europe, reduce corporate taxation, set up some kind of bargain basement trade agreement with the USA.

“The result would be a reduction in wages, reduction in public expenditure and ultimately a big reduction in living standards across Britain.”

Brexit Concerns Show all 26 1 /26 Brexit Concerns Brexit Concerns Brexit will put British patients at 'back of the queue' for new drugs Brexit will put British patients at the “back of the queue” for vital new drugs, the Government has been warned – forcing them to wait up to two years longer A medicines regulator has raised the alarm over a likely decision to pull out of the European Medicines Agency (EMA), as well as the EU itself. ealth Secretary Jeremy Hunt dropped the bombshell , when he said he expected the UK would quit the EMA – because it is subject to rulings by the European Court of Justice. Getty Images Brexit Concerns London to lose status as 'gateway to Europe' for banks One of Germany’s top banking regulators has warned that London could lose its status as “gateway to Europe” for the banking sector after Britain quits the European trading bloc. Andreas Dombret, who is an executive board member for the Bundesbank—Germany’s central bank—told a private meeting of German businesses and banks earlier this week in Frankfurt that even if banking rules were “equivalent” between the UK and the rest of the EU, that was still “miles away from [Britain having] access to the single market”, the BBC reports. Jason Hawkes Brexit Concerns Exodus The number of financial sector professionals in Britain and continental Europe looking for jobs in Ireland rocketed in the months after the UK voted to leave the European Union Shutterstock Brexit Concerns Brexit is making FTSE 100 executives richer Pay packages of many FTSE 100 chief executive officers are partly tied to how well share prices are doing rather than the CEO’s performance -- and some stocks are soaring. ritish equities got a boost since the June vote because the likes of Rio Tinto, Smiths Group and WPP generate most sales abroad and earn a fortune when they convert these revenues back into the weakened pound. Sterling’s fall also made UK stocks more affordable for overseas investors. Rex Brexit Concerns Theresa May: UK to leave single market Theresa May has said the UK "cannot possibly" remain within the European single market, as staying in it would mean "not leaving the EU at all". Getty Brexit Concerns Lead campaigner Gina Miller and her team outside the High Court Getty Brexit Concerns Raymond McCord holds up his newly issued Irish passport alongside his British passport outside the High Court in Belfast following a judges dismissal of the UK's first legal challenges to Brexit PA wire Brexit Concerns SDLP leader Colum Eastwood leaving the High Court in Belfast following a judges dismissal of the UK's first legal challenges to Brexit PA wire Brexit Concerns Migrants with luggage walk past a graffiti on a wall as they leave the 'Jungle' migrant camp, as part of a major three-day operation planned to clear the camp in Calais Getty Brexit Concerns Migrants leave messages on their tents in the Jungle migrant camp Getty Brexit Concerns The Adventist Development and Relief Agency (Adra) which distributes approximately 700 meals daily in the northern Paris camp states that it is noticing a spike in new migrant arrivals this week, potentially linked the the Calais 'jungle' camp closure - with around 1000 meals distributed today EPA Brexit Concerns Migrant workers pick apples at Stocks Farm in Suckley, Britain Reuters Brexit Concerns Many farmers across the country are voicing concerns that Brexit could be a dangerous step into the unknown for the farming industry Getty Brexit Concerns Bank of England governor Mark Carney who said the long-term outlook for the UK economy is positive, but growth was slowing in the wake of the Brexit vote PA Brexit Concerns The Dow Jones industrial average closed down over 600 points on the news with markets around the globe pluninging Getty Brexit Concerns Immigration officers deal with each member of the public seeking entry into the United Kingdom but on average, 10 a day are refused entry at this London airport and between 2008 and 2009, 33,100 people were detained at the airport for mainly passport irregularities Getty Brexit Concerns A number of global investment giants have threatened to move their European operations out of London if Brexit proves to have a negative impact on their businesses Getty Brexit Concerns Following the possibility of a Brexit the UK would be released from its renewable energy targets under the EU Renewable Energy Directive and from EU state aid restrictions, potentially giving the government more freedom both in the design and phasing out of renewable energy support regimes Getty Brexit Concerns A woman looking at a chart showing the drop in the pound (Sterling) against the US Dollar in London after Britain voted to leave the EU Getty Brexit Concerns Young protesters outside the Houses of Parliament in Westminster, to protest against the United Kingdom's decision to leave the EU following the referendum Getty Brexit Concerns Applications from Northern Ireland citizens for Irish Passports has soared to a record high after the UK Voted in favour of Leaving the EU Getty Brexit Concerns NFU Vice President Minette Batters with Secretary of State, Andrea Leadsome at the National Farmers Union (NFU) took machinery, produce, farmers and staff to Westminster to encourage Members of Parliament to back British farming, post Brexit Getty Brexit Concerns The latest reports released by the UK Cabinet Office warn that expats would lose a range of specific rights to live, to work and to access pensions, healthcare and public services. The same reports added that UK citizens abroad would not be able to assume that these rights will be guaranteed in the future Getty Brexit Concerns A British resident living in Spain asks questions during an informative Brexit talk by the "Brexpats in Spain" group, about Spanish legal issues to become Spanish citizens, at the town hall in Benalmadena, Spain Reuters Brexit Concerns The collapse of Great Britain appears to have been greatly exaggerated given the late summer crowds visiting city museums, hotels, and other important tourist attractions Getty Brexit Concerns The U.K. should maintain European Union regulations covering everything from working hours to chemicals until after the government sets out its plans for Brexit, said British manufacturers anxious to avoid a policy vacuum and safeguard access to their biggest export market Getty

His announcement comes after he used a speech to suggest Europe’s centre-left parties must reject the establishment – or watch the populist far-right win across the continent. In a speech to Labour’s European sister parties in Prague, the Labour leader warned that the populist right had correctly identified problems with the prevailing economic model.

But he argued the solutions of those anti-immigrant, anti-EU, and anti-Islam parties were only “toxic dead ends” that would not solve people’s problems. Mr Corbyn’s comments come a day before Austria votes in a rerun of its presidential election – in which a far-right Norbert Hofer could be on the verge of victory.

A Conservative spokesman said: “Yet again, Labour have shown they want to frustrate the will of the British people by slowing down the process of leaving the European Union and trying to tie the Government’s hands in a negotiation.

“Labour are utterly out of touch with the values of working people across our country.