The chair of UKIP’s Glasgow branch has quit the party claiming there is a “democratic deficit”.

Sarah Devenney, 37, follows several other high profile UKIP members to walk away in recent weeks.

Many are unhappy about a decision to allow the party’s leader in Scotland, David Coburn MEP, to pick Holyrood candidates.

Democratic decision-making functions in Scotland were suspended by the London-based party hierarchy in 2013 during a period of infighting.

These so-called “special measures” meant that members were not asked to vote for their chosen Scottish Parliament candidates.

Read more: Former UKIP aide says David Coburn is Scotland's answer to Austin Powers

Coburn previously said publicly that Holyrood candidates would be selected and ranked by an assessment team led by UKIP director Paul Oakden, so that the MEP could “avoid any accusation of bias”.

But it was revealed in March that Mr Oakden contradicted Coburn in a subsequent email to party members which stated that the National Executive Committee “have determined that the UKIP Leader in Scotland should devise a list, including candidate rankings for each region of Scotland.”

Mr Coburn later denied that he was involved in the process and insisted he was “not imposing anyone on anyone”.

However, an email from party chairman Steve Crowther – uncovered on Sunday - confirmed that Mr Coburn was indeed given control, and then placed himself top of UKIP’s regional list in the Highlands and Islands.

Read more: UKIP candidate warns party on 'brink of disintegration' in Scotland

Ms Devenney said she joined UKIP because she is “passionate” about campaigning for the UK to leave the European Union but now believes UKIP is “not the vehicle to achieve a Brexit vote”.

Writing on the UKIP Glasgow branch Facebook page she said: “I have come to feel that the internal democratic deficit of the party has inhibited the ability of Scottish branches to campaign for Brexit. I am not alone: the majority of UKIP’s Scottish chairmen are likewise minded.

“It is three full years since Scottish members were allowed to elect a Scottish committee and two and a half years of special measures.

“Members of UKIP’s NEC, some of whom are presently Assembly candidates in Wales, must be asked whether the democratic deficit – special measures - in Scotland prevails with their backing.

“Also, why were Welsh members deserving of a ballot on candidates and Scots not? Can these decisions be linked with Farage’s recent dismissal of a petition signed by 5 out of 8 Scottish chairmen as ‘totally and utterly irrelevant’?

“I expect the party to respond with a personal attack, when instead it might recover some credibility by addressing the constitutional points raised. Saying it is just a handful of disgruntled critics is no longer going to cut the mustard as a retort. The Scottish electorate won't be taken for mugs.”

Former aide to David Coburn and Glasgow branch secretary, Robert Malyn, who quit UKIP on Sunday, backed the move by the chair of the Glasgow branch – the largest in Scotland which could now be dissolved.

“Until the democratic deficit in UKIP Scotland is addressed, UKIP will never gain the popular support that it needs to grow,” said Mr Malyn. “The party in Scotland needs to be taken out of the shackles of special measures, otherwise UKIP is damaged goods and not fit for purpose.”

Former vice chairman of UKIP Scotland Malcolm Mackay, who quit the party in 2014, added: “I resigned over these same issues two and a half years ago. I would like to fully support Sarah Devenney and all of those who, like the Glasgow chair, stand up for the principles she espouses in this resignation.

“UKIP is not Brexit and the Brexit campaign is not UKIP, and David Coburn MEP is neither.”

The Scottish arm of the anti-EU party has been beset by splits in recent months. Holyrood candidate Euan Blockley quit in March and only yesterday the chairman of the Edinburgh branch, Alan Melville, who tops UKIP's Lothian list, said the party in Scotland is close to “all-out civil war”.

David Coburn has dismissed the criticism as “a lot of tosh”.

Responding to Ms Devenney’s resignation today, a party spokesman said: “Without UKIP there would not be an EU referendum, so the argument we are not a vehicle for Brexit is clearly ignorant nonsense, and the fact that someone that doesn’t understand that simple idea is leaving the party is hardly bad news for us.

“Perhaps if the chairman of Glasgow had actually done anything in the campaign rather than just be bitter that she wasn’t chosen to top the list, she would have discovered that growing number of Scots will support UKIP this year.

“As soon as she knew she had not been selected as number one on the list, she decided not to stand and seemingly did no campaigning, so no one in the party will be taking lessons from her in acting in the best interests of UKIP or the Brexit campaign.

“With that in mind, it seems that the process that prevented her getting the top spot on the list was very effective in separating the wheat from the chaff.

“Anyone that leaves in the last week of a campaign, is not and possibly never has been interested in the cause, nor their fellow candidates or the party, they are just out to cause damage.

“This is all about their private careerist egos, that frankly politics would be better off without.”