The SNP said Alex Salmond had the right to be included as a party leader
The SNP may take legal action if Alex Salmond is not allowed to take part in a UK party leader TV debate ahead of the next General Election.
The BBC, ITV and BSkyB jointly proposed three live debates between the Labour, Tory and Liberal Democrat leaders.
SNP Finance Secretary John Swinney said going to court was not being ruled out, but said it was more preferable to come to an agreement with the broadcasters.
Opposition parties accused the SNP of bullying tactics.
Tory leader David Cameron and Liberal Democrat leader Nick Clegg have welcomed a TV debate, while Gordon Brown has now said he was willing "in principle" to take part.
Mr Cameron has told the BBC he wants a respected independent figure to oversee the negotiations for the TV debates.
But the SNP has threatened to seek to block the screening in Scotland of any debate which did not include Scottish First Minister Mr Salmond.
Mr Swinney told BBC Scotland's Politics show the SNP was the party of government at Holyrood, adding that the UK debates would discuss issues of importance to Scotland, such as the future of nuclear submarines on the Clyde.
Mr Swinney said the SNP was prepared to be flexible, saying of the current arrangements: "It deprives the voters in Scotland of hearing the breadth of political choice that quite clearly exists here in Scotland about the input of Scotland into the UK General Election."
Current plans would see the three main UK party leaders take part
On the issue of legal action, he added: "That might be a possibility, but, long before we get to that judgement, we have to have full and open discussions with the broadcasters about the arrangements that can be put in place."
Also speaking on the programme, shadow Scottish secretary David Mundell said it was not appropriate for Mr Salmond to take part in a debate about who should be the prime minister of Britain.
Labour described the SNP's option of going to court as a "sinister threat", and claimed, along with the Liberal Democrats, the Nationalists were attempting to bully broadcasters.
The broadcasters have said they would each seek "to make suitable arrangements for ensuring due impartiality across the UK", but have not yet explained how that would be achieved.