Prime Minister Theresa May has been warned by a Labour stalwart that to "crash out" of the EU with a no-deal Brexit would be "grossly reckless and irresponsible".

Labour's leader in the House of Lords, Baroness Smith of Basildon branded the Withdrawal Agreement "inadequate" and said a no-deal scenario must be rejected.

But Lords leader Baroness Evans of Bowes Park defended the deal as being in the national interest and vital to protect jobs.

Urging peers to support the deal, Lady Evans said: "This is a good deal and as European leaders have made clear, the only one on offer."

The chamber was crowded as peers began a marathon three-day debate on the deal, with nearly 200 speakers, after the Government's bruising defeats in the Commons yesterday.

Lady Evans said that by supporting the deal "we will be protecting jobs, ending the jurisdiction of the European Court of Justice in the UK and securing the ability to strike free trade deals around the world".

The deal maintains a "strong and close relationship with our European allies while allowing us to forge new partnerships around the world", she said.

Lady Evans warned: "The only certainty if this deal is rejected in the Commons is uncertainty. That's not good for business, our economy, our political system, and our citizens. It is not the right path to follow."

She said there is no alternative on the table and defended the controversial Northern Ireland backstop as a last resort insurance policy, without which there would be no deal.

But Lady Smith said: "To crash out of the EU without arrangements in place for co-operation on trade, agriculture, fisheries, security, energy and the environment would be grossly reckless and irresponsible."