This site holds no brief for either the Greens or the SNP.  But there is no good reason to exclude either altogether – or Plaid Cymru, or Respect – from the proposed general election TV debates.

If UKIP should be included as the broadcasters propose – on the ground that it has representation in the Commons and is a growing force – then so should the Greens, since the same logic applies.

Ditto the SNP, which could well hold the balance of power at Westminster next May.  Is it seriously being claimed that a UK general election is an English-only affair?

And ditto, too, Plaid Cymru.  Some would draw the line at the British mainland parties.  I would include the Northern Ireland ones that are willing to send MPs to Westminster if elected.

The most straightforward way to proceed is to have several debates between the two men likely to be Prime Minister after the next election – that’s to say, David Cameron and Ed Miliband.

Three is perhaps the best number to settle on, given the range of issues involved.  And a separate debate should take place that includes every party with at least one seat in the current Commons.

The SNP has apparently “not ruled out taking legal action over the plans to exclude them from the UK-wide live TV debates”.

In doing so, this separatist party is, ironically, making a Unionist case – or at least a case for fair, clear, UK-wide treatment of the election debates.  It is right to do so.