A PRO-UNION blogger who was barred from Ukip for questioning the Holocaust has become the first individual to register as an official campaigner in the independence referendum.

Alistair McConnachie, who disputes that Nazis used gas chambers to murder Jews, is now legally entitled to spend up to £150,000 in support of a No vote.

He registered with the Electoral Commission as a so-called "permitted participant" last week, a sign he intends to spend at least £10,000 of his own money or donations.

Glasgow-based McConnachie, 48, was Ukip's Scottish organiser between 1999 and 2001, and stood as a Ukip candidate five times.

However, in late 2001, the party refused to renew his membership because of comments he made about the killing of Jews at

In an email to party members, he said: "I don't accept that gas chambers were used to execute Jews for the simple fact there is no direct physical evidence to show that such gas chambers ever existed ... There are no photographs or films of execution gas chambers ... Alleged eyewitness accounts are revealed as false or highly exaggerated."

McConnachie also claimed the Pope was duped over the Holocaust and attacked the Board of Deputies of British Jews, prompting some Ukip members to resign from the party's executive.

The controversy began in 2000 when McConnachie wrote to newspapers questioning how many Jews had died at Auschwitz and citing American "expert" Fred Leuchter, who claimed there were no gas chambers at the concentration camp.

McConnachie also accused the Board of Deputies of "seeking to establish a monopoly in the marketplace of ideas" because it complained to the BBC for running two interviews with the Holocaust denier David Irving.

Ukip initially expelled McConnachie for five years for bringing the party into disrepute, but this was reduced on appeal to a one-year suspension from the executive.

At the time, McConnachie said he had been defending his "private right to free speech within the law" but Ukip refused to renew his membership. After Ukip, McConnachie formed his own party, Independent Green Voice, and stood as its candidate three times.

In 2007, he wrote that he was not a Holocaust denier but was "quite prepared to accept that six million Jews perished in the Holocaust", but retained his doubts about gas chambers.

"Regarding the Holocaust, the most that could be said is that I've questioned, and doubt from a historically interested point of view, some aspects, specifically with regard to the existence of execution gas chambers."

Since March 2012, McConnachie has run a pro-Union website called aforceforgood.org.uk, which carries essays and graphics, many of the Union flag and the phrase "Gonna vote naw". It argues against more powers for Holyrood because "the presence of a significant separatist movement", in the form of the SNP, means "devolving power will always be potentially dangerous to a union".

SNP MSP Stewart Maxwell called on the pro-Union Better Together campaign to distance itself from McConnachie, saying: "Mr McConnachie's repulsive views denying the Holocaust are stomach-churning - even Ukip disciplined him for that.

"He is entitled to vote and work for a No, but he has gone further than that by formally associating himself with the No campaign. Therefore, in the interests of decency and a civilised debate, we would urge David Cameron to dissociate himself from Mr McConnachie and suggest that [Better Together chair] Alistair Darling writes to him requesting that he deregister as a permitted participant."

A Better Together spokesman said: "The fact that we had to Google this guy tells you all you need to know about his links to our campaign."

McConnachie hung up on the Sunday Herald when contacted for comment.