An English Labour MP who has joined Westminster's main forum for Welsh affairs has said she would step aside if Welsh Labour MPs want to sit on it.
Colne Valley MP Thelma Walker said she agreed to join the Welsh Affairs Committee because she thought it was important it had the full membership of 11 MPs.
She replaces Aberavon Labour MP Stephen Kinnock, who stepped down to concentrate on other committee work.
He is on the Commons Brexit committee.
Mr Kinnock also sits on the European Scrutiny Committee.
Plaid Cymru Parliamentary leader Liz Saville Roberts said: "It is disappointing that the Labour Party, with 28 Welsh MPs, can't fill four seats on the Welsh Affairs Committee."
"Stephen Kinnock didn't turn up to a single meeting in this Parliament, so he has set a low bar for his successor.
"But to replace him with an MP from Yorkshire to serve on a committee dealing with the affairs of Wales is an insult to the people who voted for the Labour Party in the election.
"Serving on the Welsh affairs committee is a privilege and I find it surprising that not a single Labour MP from Wales felt able to take up the opportunity to represent their party and their country on the committee."
Mrs Walker, a former headteacher, said: "I believe that my Yorkshire constituency and many Welsh constituencies face lots of the same issues.
"From farming and the impacts of Brexit, to issues with transport and broadband speeds.
"I will be a voice for Yorkshire, but also for communities in Wales who are equally affected by this government's austerity driven agenda.
"I would be more than happy to step aside if one of my Welsh Labour colleagues would like the opportunity to be on the committee, but in the mean-time I felt it was important the committee had full membership."
Mr Kinnock said he had been a very active member of the Welsh Affairs Committee before June's general election but now found himself on three committees.
He said: "If I could have remained on all three committees then I would, but there aren't enough hours in the day and committee sessions often overlap.
"It is vital committees properly scrutinise and hold the government to account, and I wouldn't have been able to do a proper job on any of the committees if stayed on all three."
A Welsh Labour spokesperson said: "We make no apology for drawing on the experience and commitment of our whole movement in order to best serve the people of Wales."
Labour says 13 of its 28 Welsh MPs are frontbench spokespeople who do not sit on select committees. Another four are opposition whips.
Of the remaining MPs, four are on the Welsh Affairs Committee, with the remainder sitting on other select committees.