Amanda Platell, executive editor of the Express on Sunday, approved a story headlined "Brazilian student who is Mandelson's close friend" in November. The story prompted the former cabinet minister to contact Ms Platell's boss, Express editor Rosie Boycott, who is also a friend of Mr Mandelson.
The four most senior executives on the title could all depart because of the affair.
In response to the bloodletting at the newspaper, Conservative MP Julie Kirkbride tabled an Early Day Motion in the House of Commons today outlining opposition to what she calls Mr Mandelson's "unacceptable pressure on the editors of the Express on Sunday to water down the story."
The motion also refers to other alleged behind-the-scenes manipulation by Mr Mandelson in which a senior journalist for The Sun was sacked after making comments about the Hartlepool MP on television.
The Express denied yesterday that the article about Mandelson's friend, Reinaldo Avila da Silva, was connected to changes in the Sunday title.
However, senior sources on the title confirmed that relations between Ms Boycott and Ms Platell had been strained. "Rosie and the paper gave assurances to the Press Complaints Commission that an interview with and photographs of Reinaldo had been given freely. That proved to be incorrect. That was not good journalism," said a senior Express executive.Reuse content