MPs who will today be part of a parliament which makes history, have spoken of their views on the implications of Article 50 being triggered.

The issue of whether or not to leave the EU created a bitter divide among the UK's parliamentarians.

Even now, with Brexit under way, opinions are split over what is the best direction of travel for the UK - with Britain's membership of the single market top of the agenda.

Barrow and Furness MP, John Woodcock, said: "There has been so much hype and anticipation of Article 50 being triggered today that the event itself is likely to be something of an anti-climax.

"Rather than the UK freeing itself from the European Union with one heroic bound, the process given the green light today will be the most complex in generations of British governance.

"The UK will be negotiating with 27 different countries simultaneously, through the European Commission but also presumably directly through the prime minister, foreign secretary and others.

"I worry about the basic competence of the current set of ministers to get the best deal for Britain in this incredibly testing environment.

"But I am most concerned that the direction the government has set for the negotiation risks badly damaging jobs and standards of living across the country.

"It is an act of dogmatic folly to rule out the option of the UK remaining part of the single market after we leave the EU.

"Coming out of the single market, and the related customs union, will almost certainly place barriers between us and our nearest trading partners, damaging the economy and costing local jobs.

"I want Britain outside of the European Union to remain the open and outward-looking country that brought us so much success through history. That means remaining part of the single market once we leave. The government was given a narrow mandate by the British people to leave the EU in last year's referendum. It has no mandate whatsoever to do so in a way that will damage our economy for generations to come."

Meanwhile, a new row has erupted over claims that Theresa May's plans risk failing to fulfil the promises made by Leave campaigners and could lead to the UK exiting the European Union without a trade deal.

Pro-EU former ministers including Tory former education secretary Nicky Morgan, Liberal Democrat ex-deputy prime minister Nick Clegg and Labour's Chris Leslie said Mrs May's decision to begin the Article 50 process meant the "phoney war" over Brexit was now over.

The three former frontbenchers, part of the Open Britain pressure group, said that as "realists", they feared the prime minister's plans for Brexit will not deliver the outcomes promised by the government and the Vote Leave campaign in last year's referendum.

They said there was "no mandate for the form Brexit takes" but "a clear direction of travel has been set by the government - and it is largely based on that set by the Vote Leave campaign".

Meanwhile, leader of the Liberal Democrats and south Cumbria MP, Tim Farron, accused the prime minister of pursuing a Brexit which could be hugely damaging for Cumbria.

He said: "Theresa May has a mandate to pursue Brexit but not a mandate to pursue a massively damaging hard Brexit that will leave British businesses outside the single market and facing huge tariffs on exports.

"She has chosen an extreme and divisive Brexit which could be massively damaging for Cumbria. The single market is vital for jobs and for business, yet the government has resigned itself to leaving it before even trying to negotiate.

“Ultimately, Theresa May will come back from Brussels with a deal. The question now is who signs off that deal – should it be politicians or should it be the people?

"The Liberal Democrats are clear that this momentous decision, the final say on our new relationship with Europe, should be put to the people in a referendum. The people must have the final say.”

However, a think tank says Mrs May should not try and stay "half-in, half-out" of the European Union customs union and should instead pursue a clean break.

Open Europe said the prime minister should pull Britain out of the union entirely before striking a new "customs facilitation agreement" as part of a comprehensive free trade deal, similar to those enjoyed by Switzerland and Canada.

She should reject a "Turkish model" as it is built for a country on a path towards EU membership, the report said.

A "sectoral" model, with industries with complex supply chains like aerospace, automotive or chemicals, inside a customs union and others outside, would be "complex, legally difficult, and probably un-negotiable", the think tank said.

A comprehensive UK-EU free trade agreement would ensure tariff-free trade and minimise customs delays, said Open Europe.

But the report acknowledged that leaving the customs union would cause one-off costs to adapt to a new regime and "ongoing frictional costs".