The SNP MP Joanna Cherry has resigned from the party’s national executive committee.
She said “a number of factors” had prevented her fulfilling her mandate “to improve transparency and scrutiny”, and “uphold the party’s constitution”.
Her decision comes after MP Douglas Chapman stood down from his role as party treasurer citing a lack of “support or financial information”.
The Edinburgh South MP was elected to the SNP’s governing body last year.
She announced her decision to quit on Twitter, but said she would be making no further comment at this stage.
Ms Cherry, a QC, played a leading role in legal battles with the UK government during the Brexit process, but has clashed with a number of SNP colleagues at Westminster over transgender rights and the party’s strategy for independence.
Her resignation comes just 48 hours after Dunfermline and West Fife MP Douglas Chapman stepped down as the party’s national treasurer, saying he had not been given enough information to do his job.
It is understood his decision is linked to a continuing row about the use of cash ring fenced for a second independence referendum. Both MPs were among those pressing for progress towards a second vote.
Questioned about Mr Chapman’s resignation, Deputy First Minister John Swinney told the BBC’s Sunday Show he could not understand what had prompted the decision.
Asked whether Police Scotland was investigating “£600,000 of SNP funds that was raised by activists and campaigners and perhaps diverted elsewhere?” Mr Swinney replied: “Not to my knowledge, no.”
Meanwhile former MSP Marco Biagi also announced he was “choosing to move on” from a post at SNP HQ working on the groundwork for the case for independence, less than six months after starting.
There has long been speculation about discontent within the famously disciplined ranks of the SNP.
This is chiefly centred around impatience over the party’s drive for independence, but has crept across a range of other topics including gender politics and the tight, rather opaque decision-making circle around leader Nicola Sturgeon.
A slate of candidates from somewhat more critical wings of the party was elected to its governing body, the NEC, six months ago.
However many have since dropped out – some leaving the party entirely to join Alex Salmond’s alternative vehicle, Alba. Others, like Ms Cherry and Mr Chapman, have stepped away making reference to “transparency” and “scrutiny” but crucially refusing to make any more specific comment.
On the one hand, this is a signal that discontent within parts of the SNP has not gone anywhere.
However with yet another election win in the bag and her critics walking away from positions of potential influence, it also underlines that Ms Sturgeon’s grip on the party is stronger than ever.