The Scottish National Party (SNP) leader and Scottish First Minister, Alex Salmond, will seek to pre-empt the first-ever General Election TV leaders' debate with a UK-wide broadcast.
The SNP have decided to replace a planned party election broadcast - scheduled for screening just before the first leaders' debate on ITV on Thursday 15 April 2010 - with a "specially recorded address" that aims to take the SNP's "alternative message to the cuts agenda of the London parties", as they put it, into homes across the whole of the United Kingdom.
The SNP says Mr Salmond will use the broadcast to challenge what he will brand the "cosy Westminster consensus" on budget cuts which the Labour, Tory and Liberal Democrat leaders are likely to agree on - albeit with slightly different emphases, and more or less detail - during the ITV debate.
Salmond will say that the broadcasters should have ensured a "real debate, with all political voices" in order to offer viewers an alternative to the "Metropolitan machine" politics of the London parties.
Predicting a "long-winded debate about English health, crime and schools", the SNP leader will also point out that the debate will be "largely irrelevant to a Scottish audience."
Previewing the party election broadcast, Mr Salmond said today: "Broadcasters sometimes trail their programmes by saying they can be seen 'except for viewers in Scotland'. In the same way, this leaders' debate is being directed at the electorate - except for viewers in Scotland."
He continued: "The so-called domestic issues which will be debated - things like health, education and policing - are all controlled in Scotland by Holyrood. As such this discussion will be totally meaningless to viewers in Scotland."
Salmond declared: "The broadcasters have ensured Scotland's voice is not being properly heard in the leaders' debates. But our special party election broadcast will take our message to people right across the UK. And for those watching in Scotland, it will let them know there is a real alternative to the decade of despair threatened by the London parties - and that alternative is voting SNP on 6 May for local and national champions."
The 'big three' parties are likely to ignore the challenge, and in Scotland they accuse the Scottish National Party of opportunism.
Labour, Tories and Lib Dems are also united in claiming that the SNP and its Welsh equivalent, Plaid Cymru, cannot make a real impact on politics at a UK level.
Plaid and the SNP respond by saying that this reflects the English-dominated arrogance of the main parties, as well as the unfair and undemocratic nature of the voting system and of Westminster-dominated politics in Britain.
The SNP election broadcast will be screened on Thursday evening - before the ITV leaders' debate begins at 8.30pm, at the following times:
BBC 1 Scotland 18:55
BBC2 Scotland 17:55
Channel 4: 19:55 (UK-wide)
Channel 5: 19:25 (UK-wide)