Mandelson partner in citizenship row
The decision to give a UK passport to Reinaldo Avila da Silva was unfavourably compared with the repeated failure of Duncan Fletcher, the Zimbabwean coach of the England cricket team, to be given citizenship.
Ann Winterton, the Conservative MP for Congleton, said she intended to take the issue up with Charles Clarke, the Home Secretary.
"It is absolutely disgraceful," she said. "It shows there is no equity at all in the system whereby da Silva can so easily obtain British citizenship, yet Mr Fletcher, who has been trying for years, is regularly refused."
Mrs Winterton was sacked from the Tory front-bench in 2002 after allegedly making a racist joke in an after-dinner speech.
Gerald Howarth, the Tory MP for Aldershot, also questioned the decision. "This demonstrates that the stench of nepotism covers Mr Blair and his entourage, and people will be absolutely disgusted," he said. "It illustrates that yet again someone close to a former minister is able to sail through the bureaucratic system.
"I wonder who the public would feel has done more for this country - Mr Fletcher, the man behind a glorious summer of cricket, or Mr Mandelson's consort."
Mr Fletcher has been based in Britain since 1997. However, his citizenship applications appear to fall foul of one of the details in the legal criteria for citizenship.
As well as "being of sound character and mind", a successful applicant must have been resident in the UK for five years and must not have spent more than 450 days abroad during that time.
Mr Fletcher's extensive touring with the England team would likely take him past that 450-day limit.
While it has been reported that Mr Mandelson and Mr da Silva have registered their union under planned "civil partnerships" legislation, no such relationships will be recognised until later this year.
The Home Office declined to comment on individual citizenship applications, but insisted that the normal rules are applied to all cases.