The Scottish National Party and Plaid Cymru have responded with frustration and anger after the BBC Trust refused a complaint about their exclusion from the Corporation's TV prime ministerial debate.
The parties, who are both involved in governing relationships in their countries, had not been allowed to put their case in person.
The second of the three 'Leaders' Debates', also characterised as Prime Ministers' debates in order to justify the exclusion of leaders in Scotland and Wales, took place on Sky TV, relayed on the BBC, last night (22 April 2010).
The Scottish and Welsh nationalists wanted their leaders to be included in the three live TV clashes between Labour's Gordon Brown, the Tories' David Cameron and the Liberal Democrats' Nick Clegg.
The BBC Trust - which has been accused of being supine in its defence of the company's policies - said it was "appropriate" to exclude the SNP's Alex Salmond, First Minister of Scotland, and Plaid's leader Ieuan Wyn Jones, who is also involved in government.
Mr Salmond said the BBC's decision was "a democratic disgrace", adding that "the decision shows that the BBC has given up all pretence of being a national broadcaster for Scotland."
The BBC Trust has also come under fire for defending the Corporation's refusal to broadcast a charitable appeal for victims of the Gaza conflict, under pressure from pro-Israeli government lobbyists, and their refusal to countenance non-religious contributors to the 'Thought for the Day' radio slot on spirituality and ethics.
The Trust, which is not fully independent, has also been accused of being too cosily accommodated to the "London and English establishment consensus."
The latest decision is likely to strengthen that impression, say critics in Wales and Scotland - who also emphasise the vital importance of the BBC, and reject ideas to break-up or privatise it.
"Fairness and impartiality have been thrown out of the window in what amounts to blatant discrimination against both parties and both countries," said Mr Salmond.
Plaid's director of elections, Helen Mary Jones, commented it was "astonishing" that the BBC Trust had not allowed either it or the SNP to put their case across in person.
"Having shown complete disregard for Plaid and the democratic process of our nation, the BBC can no longer claim to be a national broadcaster for Wales," she declared.