Ulster Unionists MPs at Westminster believe Independent News & Media's bid for the Belfast Telegraph will be successful and are preparing a formal request for the Competition Commission to investigate the take-over.

Ulster Unionist sources believe the £275 million sterling (#449 million) bid for the daily newspaper will be accepted by the board of Trinity Mirror later this week when it announces its preferred buyer. It is the largest bid and Ulster Unionists are bracing themselves for what they regard as "the worst case scenario" should Independent News & Media emerge successful.

The Competition Commission is aware of the opposition among Ulster Unionist MPs. It would be formally asked to investigate a buy-out on the basis of the UUP's contention - rejected by Independent News & Media - that control of the Belfast Telegraph would give it a media monopoly in Northern Ireland.

Such is the level of hostility among Ulster Unionists at Westminster, that the Ulster Unionist leader, Mr David Trimble, has stepped into the debate and personally registered his disapproval of the proposed buy-out with the British Prime Minister, Mr Tony Blair, and with the Department of Trade and Industry.

In his representation to Mr Blair, Mr Trimble "underlined" the opposition to the deal publicly expressed by his deputy, Mr John Taylor, who is due to meet the Trade and Industry Secretary, Mr Stephen Byers, imminently to discuss the take-over. It is understood that Mr Trimble pressed the issue of creating a monopoly within the media in Northern Ireland and expressed his concern that the moderate Unionist editorial line of the Belfast Telegraph could be at risk.