He now faces the worst crisis of his career after a Sunday newspaper revealed that he had been taking his ministerial brief too literally by having an affair with a hitherto unknown actress, Antonia de Sancha.
Fun is always a highly subjective commodity and much of the press could not remember when they had last had so much of it. Mr Mellor, his family and Ms de Sancha did not share the almost universal joy in what used to be Fleet Street.
Mr Mellor's problem is that the story stubbornly refuses to go away, spreading like a bushfire sometimes in directions which do nothing to help his political survival.
Firstly it spawned a fierce debate over privacy and whether the press should be allowed to publish such stories. Mr Mellor is the minister responsible for deciding whether a law is to be introduced curbing the media's right to do so.
This allowed even the most strait-laced sections of the media to discuss Mr Mellor's affair in detail in the context of whether there should be a privacy law and, if so, whether he should continue to be responsible for it.
The great and the good who sit on the Press Complaints Commission might have been expected to bail out the embattled minister. But they ruled that the public has a right to know about the private behaviour of politicians.
Then Kelvin MacKenzie, the editor of the Sun, widened the debate to include political dirty tricks and double standards over privacy. He revealed that during the general election campaign, a Tory Cabinet minister had offered to give him the names of women with whom Paddy Ashdown, the Liberal Democrat leader, was alleged to have had affairs.
From Mr Mellor's point of view, it has been unfortunate that there has been no other fun around to divert the packs of reporters scouring the nation for more details. The week has been an uninterrupted tale of woe.
The Cabinet decided to impose a firm straitjacket on public spending, which will effectively pit department against department in the annual budgetary round. Social security benefits are expected to bear the brunt of the resulting cuts.
The recession continues to haunt the Government, despite some predictions that the economy would pick up in the wake of the Conservatives' election victory. Figures published on Wednesday showed that there has been a decline in high street spending.
The likelihood of mortgage rate increases threatened to deepen the economic gloom and forced the Government to cut interest rates on its new National Savings bond, to enable building societies to attract investors back.
Alison Halford, Assistant Chief Constable of Merseyside, reached an agreement which ends her two-year battle to prove that she was denied promotion because of sexual discrimination.
The deal also ends an industrial tribunal which has cost pounds 1.2m, done nothing for her reputation or that of Merseyside Police, and which has been no fun at all.