Members at the Scottish mill are being balloted following the "overwhelming rejection" of a proposed pay freeze for 2006, and a small one-off payment for 2007.

"This offer is totally unacceptable and an insult to our loyal and hardworking members at the plant," said Amicus Scotland region assistant branch secretary Willie Wallace.

In addition, Wallace said that the firm had proposed changes to staff bonus targets that he said were "unachievable".

"Industrial action is not our preferred route, we want a negotiated settlement," said Wallace.

However, he claimed that IP's refusal to discuss an improved offer had forced union members down the road of possible industrial action.

IP has said it may return to the debating table once the result of the ballot has been determined.

The ballot will close on 10 March, and if workers vote in favour of strike action, the earliest strike date would be 17 March.

The mill employs 350 staff and produces uncoated woodfree papers and office papers.