A Scottish Tory candidate in a target seat is under pressure after he shared a social media link by a far-right political party notorious for invading mosques.

Alastair Redman, who is standing for Westminster in Argyll and Bute, circulated an internet statement on hate preacher Abu Hamza by the Britain First group.

The SNP accused Redman of an "appalling error of judgment".

Redman, who is a postmaster in Islay and a director of a recycling charity, is a former council candidate who was selected in June to contest the House of Commons seat.

Argyll and Bute was held in 2010 by Liberal Democrat MP Alan Reid with a 3,431 majority, but the seat is considered to be a four-way marginal.

Although the SNP came fourth at the last general election, the Nationalists won the constituency at the 2011 Holyrood poll.

Redman has been pictured with Prime Minister David Cameron and is said to be running an energetic local campaign.

However, the candidate has been criticised for his use of social media site Facebook.

In May, Britain First posted a photograph of Hamza, who had just been convicted of terror charges in the United States, next to a statememt:

"Abu Hamza has just been found guilty of terrorism charges in New York and may face life in prison. Like and share the good news."

Redman shared the image to his Facebook friends.

Britain First was founded in 2011 by militant anti-abortion activist Jim Dowson, a Scot who was exposed by the Sunday Herald in the 1990s for having links to loyalist groups.

It is led by ex BNP councillor Paul Golding and campaigns against mass immigration and the so-called "Islamisation" of the UK.

The group attracted media attention when senior figures embarked on "Christian patrols" and staged self-described "invasions" of mosques.

Once the mosques were entered, the right wingers tried to distribute British Army issue Bibles and anti-grooming leaflets.

The actions were explained as an attempt to confront muslim elders who were perceived to be soft on terrorism.

The inflammatory approach is championed by Golding but is believed to have been too extreme even for Dowson, who told a daily newspaper:

"No matter how many times I told him [Golding] I did not want decent Muslims intimidated, he just continued doing it.

"I have come to the conclusion that no matter how hard I tried, you cannot escape from the fact that the group is being overrun with racists and extremists."

An SNP spokesperson said:

"Vile organisations that spread hate and intolerance have no place in Scotland and Mr Redman has shown an appalling error in judgement in promoting their material. The Tories have some serious questions to answer as to whether they believe this is appropriate behaviour from one of their parliamentary candidates."

A spokesman for the Scottish Conservatives said:

"Alastair agrees with the content of the photo but certainly not the source.

"This serves as a lesson for everyone to check who they're sharing material from, and not get caught out by organisations like this."