A THIRD SNP MP has resigned from the party’s frontbench at Westminster in a blow to the new group leader, Stephen Flynn.

Chris Law resigned his position as the SNP’s spokesperson for international development and climate justice late on Thursday night.

In a letter to Flynn, the MP for Dundee West outlined his achievements in the role before saying the new group leader – elected on Tuesday to replace Ian Blackford – had his “full support”.

He further 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% GNI aid target".

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

McDonald had served as the party's Westminster defence spokesperson for more than five years, while Wishart had held several positions, taking on the Department for Environment, Food and Rural Affairs (Defra) brief only recently. 

READ MORE: 'I could have seen off SNP group leadership challenge', Ian Blackford says

McDonald was voted the SNP's Parliamentarian of the Year at the party's St Andrew's Day dinner last month, just days after being named the "Best Scot at Westminster" at The Herald’s Scottish Politician of the Year awards, an award he also received from Holyrood magazine.

Wishart is the SNP's most senior MP, having served at Westminster since his election for Perth and North Perthshire in 2001.

The National: Pete Wishart

In his resignation letter, Wishart (above) took a swipe at Flynn, saying he was “bemused” as to why the party’s new Westminster leader had sought the top job.

He wrote: “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%.

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

However, the Perth and Perthshire North MP said Flynn has his “full support”, adding: “I remain at your service if you do wish to make use of my experience in the Westminster group.”

The triple resignation will do little to quell talk of a divide in the SNP, said to be between pro- and anti-Nicola Sturgeon factions. 

However, Stewart Hosie told the BBC that the rumours were "complete fiction" pushed by the SNP's political opponents.