A third SNP frontbencher at Westminster has quit his role as a revolt against the new leader Stephen Flynn grows.

Chris Law, the MP for Dundee West, announced his decision to step down as the SNP’s spokesperson for international development and climate justice just before 10pm on Thursday night. 

"After five and a half years serving as the SNP's Shadow Secretary for International Development and Climate Justice, I have decided to step down from this role. Serving in this role has been an honour and a privilege," he wrote on Twitter.

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In his resignation letter to Mr Flynn he said he had been "honoured" to work in the role and cited polling from this week which put support for independence at 56 per cent.

Mr Law outlined his achievements in the role before saying the new group leader had his “full support”.

He also hit out at the UK Government's "reckless abolishment of the Department for International Development, followed by their catastrophic decision to renege on their manifesto promise of maintaining the 0.7 per cent GNI aid target".

Mr Law’s announcement came after two other senior MPs, Pete Wishart and Stewart McDonald, also resigned their roles on the SNP frontbench at Westminster.

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Mr McDonald had served as the party's Westminster defence spokesperson for more than five years, while Mr Wishart, the SNP's longest serving MP and chair of the Scottish affairs committee, had held several positions, taking on the Department for Environment, Food and Rural Affairs (Defra) brief orecently. 

Mr Flynn defeated Alison Thewliss by 26 votes to 17 in a short contest after former Westminster group leader Ian Blackford stood down from the role last week ahead of an annual general meeting of SNP MPs on Tuesday. 

Neil Gray MSP, the SNP's international development minister and a former MP, said Mr Law had worked "incredibly hard" and had loved his job.

"Everywhere I’ve been as ID minister the respect held for my good friend Chris has been profound.

"He has worked incredibly hard and has loved doing this job incredibly well. His talents made him perfectly suited and will see him well for new and long-standing campaigns like indy," he said responding to Mr Law's resignation.

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Mr Law replied: "That’s incredibly kind Neil and it has been such a pleasure to work with you and call you a friend.

"I will continue to work in this valuable area and will also have more time to research and develop new ideas. Thank you for your continued support."

SNP supporter Dr Siobhan Walsh said the news was "unsettling" and said party members should be given an explanation of what was happening.

"All this is very unsettling. Are SNP members not owed an explanation as to what is going on down there or are they in such a bubble that they don’t care? I’m near to leaving which seems incredible after yesterday’s poll. What happened to ‘unity’ and ‘working together as a team’?" she wrote on Twitter responding to Mr Law's announcement.

SNP activist Fiona Robertson, the party's former equalities convener, responded: "All parliamentary groups have reshuffles and disagreements. A change in leadership is often the time when people make decisions about changes in direction and their own roles and where they want to focus."

In his resignation letter to Mr Flynn on Thursday morning Mr Wishart, the MP for Perth and North Perthshire, told the new leader at Westminster he is “bemused” about why change has been pushed through at the top of the party.

The letter exposed splits within the group in London as he accused Mr Flynn, who on Wednesday sacked the chief whip Owen Thompson, of plotting against Mr Blackford who had been SNP Westminster group leader since 2017.

“I remain bemused as to the reasons why you felt it was necessary to seek a change in our leadership, particularly when we see yesterday’s opinion poll, which shows support for independence at a near all-time high and support for the SNP at Westminster at an unprecedented 51 per cent,” he said.

“Usually change of this significance accompanies failure, whereas we are looking only at sustained and growing success as a movement and party.”

He said that Flynn had been “canvassing opinion for a leadership challenge” and urged him to work closely with the party in Edinburgh.

Mr Wishart is strongly loyal to First Minister Nicola Sturgeon and helped organise Ms Thewliss’s rival leadership campaign against Mr Flynn.

Mr Flynn’s victory is being seen as a win for members who want greater independence from SNP headquarters.

Mr Wishart's comments contradict remarks by Stewart Hosie, the Dundee East MP and a backer of Mr Flynn, who claimed this week that “not one word of these divisions is true” when asked about splits in the group.