Betty Boothroyd has urged peers to use the “entire arsenal of our powers” over Brexit legislation to “limit the damage” to Parliament and the national interest.

The former Commons speaker said she could not recall “a comparable crisis of such prolonged intensity and danger to the national interest”, adding that, having campaigned for Remain, she was “bemused now to find it is the winning side that is blowing a fuse”.

The independent crossbencher said the duty of the House of Lords to examine, amend and potentially reject parts of the European Union (Withdrawal) Bill was clear regardless of how people voted in the referendum and their opinion of the Government’s “squabbling factions”.

Baroness Boothroyd addresses the Lords during the European Union (Withdrawal) Bill debate (PA)

Baroness Boothroyd gave the 100th speech of the two-day debate for the Bill’s second reading, with 190 peers listed to speak in total.

They are considering the principle of the Bill, which seeks to transfer European law into UK law.

Labour former transport secretary Lord Adonis has proposed a rare motion of regret that the Bill, which aims to transfer European law into UK law, did not provide for a second referendum on the terms of the final Brexit deal.

But the Bill is expected to clear its first hurdle in the Lords at around 10pm on Wednesday, although it faces a rough ride during committee stage.

Speaking during the debate, Lady Boothroyd said: “I do not recall a comparable crisis of such prolonged intensity and danger to the national interest and the country’s future as a United Kingdom.

“Regardless of how we voted in the referendum or what we think of the Government’s squabbling factions now, I believe that the duty on your lordships’ House is very clear.

The House of Lords considers the European Union (Withdrawal) Bill at second reading
The House of Lords considers the European Union (Withdrawal) Bill at second reading (PA)

“That duty is to assert our rights to scrutinise, to amend and if needs be to reject unacceptable parts of this Bill and to use the entire arsenal of our powers and prerogatives to limit the damage that threatens the sovereignty of Parliament and the national interest.

“Let’s put party allegiance aside on this issue. Nothing less than the nation’s future is now at stake.”

She added: “To me that’s surely more important than veiled threats to the leadership of a divided party and a possible change of government. This is no time for self-indulgence.”

Lady Boothroyd also rejected accusations by “ill-informed pundits” that the House of Lords was irrelevant.

She said: “If Parliament does its job in making this Bill and the legislation that will follow in the coming months fit for purpose, I see no reason for a second referendum. But we must end the pretence that the referendum was the last word on Britain’s future in Europe.”

The peer added: “Unless this Bill is made fit for purpose, the Prime Minister’s call for a frictionless access to the European market on which our economy depends and future generations seek to enjoy will remain a pipe dream and we, as parliamentarians, will have failed in our duty.”