The Sunday Mirror is expected to cut the price of the Sunday Mirror from £1 to 50p in London, the South East and the Midlands and the People by the same amount in the North East and Midlands.
Meanwhile, the Mail on Sunday is also expected to slash its £1.50 cover price as publishers battle for nearly 3m News of the World readers that will be without a newspaper this weekend.
In a letter to advertisers, Bailey said that print runs for the Sunday Mirror would jump by 1m, the People by 500,000 and Scottish title the Sunday Mail by 250,000.
She said: "Increased paginations across all three titles will provide a bumper editorial package for our readers and clients. In addition, for the Sunday Mirror and the People, we have put in place selective cover-price-led promotions in key geographic regions to drive sampling and maximise copy sales.
"All this activity is supported by a heavyweight national TV campaign, direct marketing, and major cross-promotion across the whole of the Trinity Mirror network of regional titles."
