SNP leaders will meet the BBC on Friday in the ongoing row about leaders of devolved nations being excluded from General Election television debates.
Prime Minister Gordon Brown, Tory leader David Cameron and Lib Dem Nick Clegg are due to take part in the presidential-style debates which will be hosted by Sky News, ITV and the BBC. Scotland's First Minister Alex Salmond and Angus Robertson, the SNP Westminster leader, are meeting BBC representatives in Edinburgh to discuss the election debates.
The First Minister called for an investigation into the BBC's decision in a letter to Sir Michael Lyons, chairman of the BBC Trust.
He said the decision has brought into question "the impartiality of the BBC in advance of the General Election".
Mr Salmond also asserts that the 76 rules governing the debate "has allowed three political parties" to dilute the role of the host David Dimbleby "from respected journalist and manager of debate to a timekeeper".
He complains that the programme audience will be recruited within 30 miles of the three English host cities where the debates are being filmed - and this "excludes direct participation of licence fee payers` from nations, regions and communities of the UK".
Mr Salmond also objects to the fact the audience will be prohibited from applauding during the debate and that camera shots of audience reaction will be restricted.
The First Minister states that the programme "effectively disenfranchises the people of Scotland and cannot do anything other than mislead viewers in Scotland due to the number of topics which will not be applicable to the situation here".
Mr Salmond and the Welsh Plaid Cymru leader Ieuan Wyn Jones on Thursday accused the BBC of bias in a joint letter to BBC Director General Mark Thompson.
Last week Mr Salmond told journalists that he questioned whether the BBC was the "British Broadcasting Corporation or the English Broadcasting Corporation". He said the BBC was in danger of alienating themselves from the devolved nations and were "in breach of any moral responsibility they have to their viewers".