UKIP is to make formal complaints after claiming it was being frozen out of debates in the run-up to the Holyrood by-election for Aberdeen Donside.

A spokesman for the party said it was in the process of complaining to BBC Scotland after it was not invited to take part in a radio hustings, Brian Taylor's Big Debate, last week and to Aberdeen Youth Council after it failed to get representation on a panel in a local hustings last night.

"We're a bit miffed. We're polling just under 9%, ahead of the Liberal Democrats who are on 4%, and yet we are not invited into these hustings but they are. We are being excluded and it's beginning to grate. There will be formal complaints. We're thinking of asking Otto Inglis (the party's by-election candidate) to turn up to these events anyway and hand out fly posters asking why he has not been invited to take part."

A spokesman for BBC Scotland said the corporation had yet to receive a formal complaint from Ukip, but explained: "As with all political parties, we have regular conversations with them about representation and we have explained to them that a combination of current political representation, their previous track record of contesting seats and current support in Scotland mean that they don't qualify (for panel participation)." Meanwhile, Alex Salmond has been accused of airbrushing independence from the by-election.

Scots Labour leader Johann Lamont claimed the SNP had kept quiet about its core policy during the hard-fought campaign. She said the Nationalists were refusing to raise the issue because the First Minister "knows what the people of Scotland really think about his independence obsession".

Mr Salmond said key SNP policies, including the council tax freeze and free prescriptions, were winning the campaign in Aberdeen Donside, where voters go to the polls on June 20.

The SNP later dismissed Ms Lamont's attack, citing press releases that have mentioned independence.