The criticism followed Mr Lang's comments on Saturday's 20,000-strong demonstration in Edinburgh, made during a BBC interview conducted before the march had begun.
The interview, filmed at the Secretary of State's official residence in Charlotte Square, Edinburgh, was broadcast on Saturday evening as the European summit was still taking place.
During the interview, Mr Lang was asked for his comments 'regarding the demonstration today'. He dismissed it as 'a piece of nonsense'. However, the demonstration had yet to begin and the full extent of the crowd or how peaceful the march would be, was as yet unknown.
Although a Scottish Office spokesman said the Secretary of State 'had not been asked about this demonstration and did not make any comment on the demonstration in the interview' the Independent viewed a BBC videotape of the interview and confirmed that Mr Lang was in fact asked, and answered, three separate questions on the consequences of Saturday's march.
The acting shadow Secretary of State for Scotland, Henry McLeish, said the entire episode had exposed Mr Lang's contemptuousness towards Scottish opinion and had revealed a 'breath- taking insensitivity'.
Alex Salmond, the Scottish National Party leader, said: 'If anyone had any doubt, it is now crystal-clear that Mr Lang sees his job as a colonial governor general.'
The multi-party march was held under the umbrella organisation Scotland Demands Democracy. At the general election opposition parties took 75 per cent of the Scottish vote.
It was a temporary show of unity among opposition parties in advance of the outcome of the Prime Minister's 'taking stock' exercise, which is expected to be announced early next year.
Mr Lang's BBC comments will not have come as a surprise; he described the march as part of the excitement of the summit, and insisted it would mean no change to policy. He said the march had not embarrassed the Government. The fact that his comments came before the march started was the cause of opposition anger.