A Scottish Labour MP has been forced to step down as his party's “Twitter tsar,” after posting a video on his blog portraying Scottish National Party leader Alex Salmond as Adolf Hitler.

Tom Harris, who stood for election as Scottish party leader last year, used footage taken from the film Downfall in a spoof video posted on his official website on Saturday. The clip, entitled ‘Joan’s Downfall’, shows Hitler ranting at generals and senior Nazis in his bunker during the collapse of the Third Reich.

Harris replaced the English subtitles from the film with his own captions, poking fun at Salmond's secrecy over a referendum on Scottish independence, as well as his decision not to sack aide Joan McAlpine, who recently suggested SNP opponents are “anti-Scottish”.

The video can be viewed here.

“The video I posted has been a well worn joke used to parody a range of public figures,” said Harris in a statement.

“However, context is everything and in the context of Johann's and my desire to improve the level of political debate on social media and the context of Joan McAlpine's much more serious statements about all political opponents of the SNP being anti-Scottish, my actions have been an unhelpful distraction for which I apologise."

Harris was handed the role of social media guru by Scottish Labour leader Johann Lamont in December. His job was to review how the party uses technology in its election campaigns and report back to deputy Scottish leader and fellow MP Anas Sarwar.

Harris's sometimes controversial use of social media has led to rows with other Twitter users in the past. In October he was forced to back down after claiming that SNP protesters had held up “anti-English” banners showing the phrase “End English rule”. However, photographs revealed that the banners actually said “End London Rule”.

“It is hugely embarrassing for Labour that one of their MPs and a leadership contender – who should have better things to do with his time – is promoting tasteless stuff like this through his official MP website,” said an SNP spokesperson.

“It is silly, negative nonsense like this that helps explain why Labour are in the doldrums in Scotland.”

A Scottish Labour spokesperson said the party needed to have “an adult debate” about Scotland's future.