Brexit bill: Jo Stevens quits Labour front bench
Jo Stevens has resigned as shadow Welsh secretary in protest at an instruction that Labour MPs must back the bill to trigger Brexit.
She told Labour leader Jeremy Corbyn she had been urged by her constituents to vote against the Article 50 bill.
Ms Stevens said leaving the EU will be a "terrible mistake" and it was "wrong" to back steps that make it inevitable.
Mr Corbyn said it was "right that the Labour Party respects the outcome of the referendum".
The Cardiff Central MP is the second Labour front-bencher to have quit over the vote.
Other Labour MPs have said they will rebel against their leader's orders.
- Court rules against government on Brexit
- Labour's Brexit dilemma
- Brexit 'to reflect interests of all UK'
The European Union (Notification of Withdrawal) Bill was published on Thursday after the Supreme Court ruled that parliament - not just the UK government alone - must vote to launch the formal process of the UK leaving the EU.
Mr Corbyn is ordering Labour MPs to back the bill, despite their misgivings, to avoid accusations of trying to overturn the result of the referendum.
Ms Stevens - the first person to quit the shadow cabinet over the bill - was the fourth MP to serve as Labour's shadow Welsh secretary since the May 2015 general election.
The city of Cardiff as a whole voted 60% Remain to 40% for Leave at the EU referendum.
One of her predecessors as shadow Welsh secretary - Pontypridd MP Owen Smith - has also said he will rebel against any instruction to vote in favour of the bill.
In a letter to Mr Corbyn, Ms Stevens said: "I accept the referendum result is to leave.
"I also accept that the parliamentary numbers are such that Article 50 will be triggered and we will leave the EU.
"But I believe that leaving is a terrible mistake and I cannot reconcile my overwhelming view that to endorse the step that will make exit inevitable, is wrong.
"I expect this to be the most important vote I will ever cast as an MP and for me it is a clear issue of principle and conscience.
"When I vote I will be representing my constituents, a great many of whom, including a great many Labour Party members and voters, have strongly urged me to vote in this way.
"That is why, in Shadow Cabinet, I argued against the imposition of a three line whip."
Ms Stevens said Prime Minister Theresa May was "now leading our country towards a brutal exit with all the damage that will cause to the people and communities we represent".
"There have been no guarantees before triggering Article 50 about protecting single market access, employment, environmental and consumer rights, security and judicial safeguards and the residency rights of many of my constituents. And no guarantees for the people of Wales," she added.
"Article 50 should not be triggered without these safeguards in place."
In response Mr Corbyn said: "I understand the difficulties that Jo, and other MPs, have when facing the Article 50 bill.
"Those MPs with strong Remain constituencies are understandably torn.
"However, it is right that the Labour Party respects the outcome of the referendum on leaving the European Union.
"We have said all along that Labour will not frustrate the triggering of Article 50 and to that end we are asking all MPs to vote for the Bill at its second reading next week."
Former Labour Welsh Secretary Lord Hain praised Ms Stevens in a tweet, saying she had been "brilliant" in the role of shadow Welsh secretary.
He described her as a "principled socialist huge talent sadly sidelined by crass whip [and] absence of clear Labour strategy or vision".
'Adrift without a paddle'
Jenny Rathbone, her Labour colleague who represents Cardiff Central in the assembly, said she was sorry to lose Ms Stevens as shadow Welsh Secretary "as she has undertaken the role with gusto".
Ms Rathbone said Ms Stevens was right to vote against Article 50 given "because no safeguards [have been] offered for Wales".
She added: "Nothing will be decided until Germany and France have had their general elections.
"So triggering Article 50 now could leave the UK adrift without a paddle."