In letters to two newspapers, 11 peers and other leading figures said Mr Vaz was being subject to a "ferocious witch hunt" and the barrage of criticisms directed at him was an "implied slur" on all Asians and black people in the UK.
Downing Street also once again extended backing to the minister, saying he had been at the centre of a "media firestorm" and insisting that "one by one the charges levelled against him have been rebutted".
But other prominent Asians have expressed disquiet that Mr Vaz and his supporters have sought to blame racism for the spotlight being cast on his affairs.
'Deep unease'
A spokesman for the beleaguered minister said he was grateful for the letter of support.
The Leicester East MP's business affairs and ministerial conduct have come under intense scrutiny since questions were first raised last month about his role in helping the billionaire Hinduja brothers secure British passports.
The letter appeared as the Commons standards and privileges committee met again at Westminster to consider an earlier complaint of alleged financial irregularities in Mr Vaz's constituency Labour Party.
The signatories, who include Labour peers Lord Patel of Blackburn, Lord King of West Bromwich, and Baroness Uddin of Bethnal Green, claimed the "witch hunt" could damage race relations.
But Labour peer Lord Desai, a former Treasury spokesman for the party, said the press was not "looking at Keith because he is Asian, but because he is a minister".
The letter, published in Tuesday's Mirror and Guardian newspapers, reads: "We are writing to express our profound disquiet at the ferocious witch hunt that has been conducted against Keith Vaz over the past two weeks, and, indeed, longer in a number of cases.
"We feel a deep sense of unease and hurt over the fact that Britain's first elected Asian minister is being subjected to an obsessive campaign of denigration, and fear for its long-term impact on the good community relations we have fought so hard to achieve, and the aspirations of young Asian and black people who wish to go into public life."
They said they found it "astonishing" that the minister should be "pilloried for having given service to the community and strongly resent the implied slur that it casts on all Asians and black people in the UK".
"We hope that even at this stage we shall see reason and responsibility on the part of the press."
Trip postponed
Mr Vaz has cancelled a planned trip to India next month.
Levy admission
Earlier, Prime Minister Tony Blair confirmed that Labour peer Lord Levy - his "personal envoy" to the Middle East and also a key high-value fundraiser for the party - met representatives of the Hinduja Foundation to discuss their support for the Millennium Dome's Faith zone.
In a Commons written reply, Mr Blair said the meeting took place on 29 October 1998, at the request of the New Millennium Experience Company (NMEC), which ran the Dome and was attended by its then chief executive Jennie Page.
The Liberal Democrat MP whose question contributed to Peter Mandelson's resignation from cabinet last month said he had a "productive meeting" with Sir Anthony Hammond who is carrying out an inquiry into the affair.
Norman Baker delivered a letter outlining 15 questions he says need to be answered to Sir Anthony.
"This was a useful and productive meeting at which I was able to impress upon Sir Anthony the key questions that need to be answered if this matter is to be laid to rest," he said.