Opening debate on the report by Lord Jenkins of Hillhead, the Home Secretary made clear that he was personally in favour of first past the post and added that in all systems "some people win, some people will lose".
Mr Straw's position puts him on a clear collision course with other members of the Cabinet, such as Robin Cook, the Foreign Secretary, and Mo Mowlam, the Secretary of State for Northern Ireland, who have spoken in favour of electoral reform.
Under the voting reforms proposed by Lord Jenkins' commission, electors will have two votes: one to elect MPs in single-member constituencies. and one for a series of bigger constituencies of "top-up" MPs on a system aimed at evening out some of the discrepancies between parties' seats and votes shares which would normally take place in the first phase.
During a noisy debate, Mr Straw said the Government would not be rushed into holding a referendum on voting reform, adding that holding one before the next general election remained an option. But he told MPs it was "less certain" in view of the commission's admission that the proposed new system could not be introduced until the general election after next.
The Home Secretary said Lord Jenkins had recommended a system which "has no parallel anywhere in the world" so it was "impossible to anticipate its consequences". The "simple truth" was the system proposed could not be in place by the next election. It would require every constituency boundary to be redrawn to cut constituencies from 659 to below 560.
He said there were "two other important reasons why the Government would not rush into holding a referendum: the need to study the Neill Committee's report on party funding and the need to consider any changes in the context of wider constitutional reform.
"We need to see how the new systems of election settle down in Scotland, Wales, London and the elections to the European Parliament. It would not be wise to embark on reform to the electoral system of the House of Commons until we are more certain of the changes that will take place in the Lords."
Dr Liam Fox, the Tory constitutional affairs spokesman, dismissed the commission as a "sham and a fraud" because it so blatantly favoured "one party, one big minority party, namely the Liberal Democrats".
In an emotional speech, former Labour minister Gerald Kaufman (Manchester Gorton) dismissed the Jenkins report as "intellectually shoddy" and "hopelessly complicated". "I seriously urge the Government to reject this report ... because if they support it they will be split against a Conservative Party that is united," he said.
In a personal attack against Lord Jenkins, who left the Labour Party in 1980 to form the Social Democratic Party, Mr Kaufman added to Labour cheers: "What he nearly did to the Labour Party then... to cause indeterminable damage... he is now trying to do in another way. This is a poisoned chalice."
But Alan Beith, the Liberal Democrat home affairs spokesman, argued that the present system produced "perverse results", and denied that the proposed system would make coalitions inevitable.
Veteran Labour left-winger Tony Benn (Chesterfield) drew laughter from all sides when he likened his role to that of an Avon lady. He said: "I heard it said by one cynic that the Labour Party is so loyal that if chimney boys were brought back in the name of modernisation we'd all go through the lobby - but turkeys don't vote for Christmas."
The real debate was about representation in the broader sense and the ability to exercise power over the executive. "I get my fax from the party headquarters every morning with quotes already in my name - `Mr Tony Benn welcomes compulsory homework for pensioners' ... - and I am supposed to take it out of the machine, pop it back in the fax machine for the Derbyshire Times and I feel less and less like a representative and more and more like an Avon lady who is told what to say when I knock at the door."Reuse content