Labour's Tam Dalyell, who was defending his seat in Linlithgow, where early indications suggested a turnout of 55%, blamed his party's campaign for voter apathy.
But Scotland's Enterprise Minister Wendy Alexander said that Mr Dalyell was "one of the mavericks in Scottish politics".
Speaking at the counting centre in West Lothian, Mr Dalyell said: "I am absolutely dismayed about the turnout but not surprised.
"All politicians, especially those of us with substantial majorities, ought to take note.
"I think the profession of politics, in my view, has been demeaned by the nature of the campaign.
"When a government party is reduced to putting up posters of Mrs Thatcher's hair on the leader of the opposition's face this is a political message, but a political message which says `to hell with the lot of you'.
"I think a 55% turnout in a British General Election speaks volumes about the low respect that politicians are now held."
Ms Alexander said it was his right to say that he did not like the poster of William Hague.
But she said: "I do not think it is negative campaigning to say that William Hague represents the the extremist right wing element reasserting itself in the Tory party."
However, the Scottish Tory MEP Struan Stevenson said it was "completely daft" to paint Mr Hague as an extremist.
Predictions of low turnouts were also reinforced by figures elsewhere in Scotland.