Fresh questions were raised last night about the role of Tony Blair's chief fund-raiser Lord Levy in the honours system, after it emerged his former secretary was awarded the MBE.
Jean Cobb received the award in the Birthday Honours of June 2002 for services to charity.
But an MP said he would take up the issue with the Cabinet Office after it was reported her charitable work involved secretarial services to three charities headed by Lord Levy - Jewish Care, Jewish Free School and Community Service Volunteers.
Lord Levy was arrested last week by police investigating allegations honours were granted for financial support to political parties, but no charge has been brought.
Nicknamed Lord Cashpoint for his ability to persuade millionaires to donate seven-figure sums to Labour, the close friend and tennis partner of the Prime Minister is understood to have been closely involved in securing £14 million of secret loans to bankroll the party's General Election campaign last year.
Norman Lamb, chief of staff to Liberal Democrat leader Sir Menzies Campbell, said it appeared Mrs Cobb's honour may have been granted because of her link with Lord Levy.
"My concern is that it looks on the face of it as if this award has been given because of who this individual worked for," he said. "I know it takes a lifetime of dedication and commitment to receive such an award. My worry is this devalues the process, brings it into disrepute.
"I will be taking it up with the Cabinet Office because I think we need answers as to why this individual has received an honour."
Labour MP Stephen Pound - a Parliamentary aide of party chairman Hazel Blears - said: "The point about having an honour like that is for something which is above and beyond what you would normally do. Hundreds, thousands of us are members of charities, we belong to charitable groups, we support them, but we don't get honours.
"What it would need is somebody who actually brings something exceptional to it. Simply being a member of a board or a member of a committee shouldn't be reason enough to get an honour.
"But the thing about this is I don't know, you don't know, the public don't know.
"Therefore some people in the public will think the worst and that is the real difficulty, until it is completely open, completely transparent and we have some idea of what the template is."