Veteran SNP MP Angus MacNeil has dramatically refused to rejoin the SNP a week after being suspended.

In a scathing letter shared on social media, the Na h-Eileanan an Iar MP lashed out at the party, describing them as a "brand name missing the key ingredient."

He said there was no "urgency for independence." 

Mr MacNeil had the whip removed week last following a row with chief whip Brendan O'Hara.

The suspension was due to expire today. During Prime Minister's Questions, he could be seen sitting behind his SNP colleagues alongside independent Margaret Ferrier, Alba's Neale Hanvey and Kenny MacAskill.

Mr MacNeil said he would stand for election again in the seat he has held since 2005. He also suggested he could stand as the SNP candidate if there was "clarity on independence" following October's party conference. 

READ MORE: MP Angus MacNeil suspended from SNP's Westminster group

In his letter, Mr MacNeil wrote: "While the SNP has many good people and the best of the three leaders at PMQs is Stephen Flynn MP, I have decided for now, not to re-join the SNP MP group, retake the whip as they call it in Westminster.

“To be clear, this is not about the conduct of the chief whip which you know I disagree with, but that is of little consequence, but it has triggered time formally away from the group which has allowed me to concentrate on what really matters, the pursuit of Scottish independence.

“I will only seek the SNP whip again if it is clear that the SNP are pursuing independence. At the moment, the SNP has become a brand name missing the key ingredient. The urgency for independence is absent."

He criticised Nicola Sturgeon's Supreme Court battle, saying the Scottish Government started the litigation "utterly clueless about how to pursue independence."

He added that they "left the Supreme Court utterly clueless about how to pursue
independence."

"The SNP still have no clear understanding that it has to use elections to negotiate Scottish independence from Westminster by getting the backing of the majority of the electorate.

"The SNP membership must have a say at conference on the policy direction, which it hasn't until now.

The tricks of the last six years of kicking the can down the road has not served Scotland well in matching our successful neighbours, instead we are trapped with Brexit in a socially failing UK.

"There has to be hope of change after the SNP Conference this October, with a lot of groundwork underway.

"Therefore, I shall not seek to re-join the SNP Westminster group but will meantime sit as an independent."

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Mr MacNeil confirmed he would "certainly be standing at the next election in Na h-Eileanan an lar on an independence platform" and that he hoped "after clarity on independence after the October conference that I will be standing for the SNP."

It's not clear what the decision means for the SNP selection process.

The party's HQ is currently finding candidates for vacant seat ahead of the next general election, widely expected next year. 

Na h-Eileanan an Iar is a key target for Labour, with former Daily Record journalist Torcuil Crichton aiming to win the constituency. 

Alba's Westminster leader, Mr Hanvey said Mr MacNeil would be "a great loss to the SNP."

He added: "The total confusion over independence strategy is causing fundamental problems for the SNP.

"The way forward must be to fight the election on a Scotland United for Independence platform, cross party and non party, appealing directly to the 50 per cent of the population who back freedom.

"If the election was to be fought on an independence mandate does anyone believe that so many SNP MPs would be standing down? To restore morale the SNP must rededicate itself to its historic mission of independence."

Scottish Tory Chairman Craig Hoy said: “This is a devastating verdict from one of the SNP’s longest-serving MPs.

“Angus MacNeil’s decision to remain outside of the SNP because he believes there is a lack of strategy on delivering independence shows that the iron discipline which was once the hallmark of the SNP is now non-existent.

“Even on their dream of breaking up the United Kingdom, an SNP MP cannot resist taking aim at the party’s leadership. As his colleagues quit their seats, this is a thinly-veiled threat to stand against his party in the Western Isles."

The SNP has been approached for comment.