Candidates and campaigners should avoid any home which has received a postal vote in the May local elections, according to the leader of Birmingham's Labour group.
Sir Albert Bore, former leader of the city council, is urging all parties to sign up to an agreement to ensure there can be no allegations of fraud.
He wants party representatives to promise not to set foot in any property which contains a postal voting form.
It follows a high-profile court case last year in which an election court ruled there had been "widespread fraud" involving postal ballots in six city council seats won by Labour in June 2004.
As a result, six Labour councillors and the party worker were officially reported as being guilty of corrupt and illegal practices.
Election commissioner Richard Mawrey QC accused the Government of being "in denial" about the potential for fraud caused by measures to make it easier to apply for a postal vote.
The Electoral Commission has introduced rules banning candidates and party workers from touching anyone else's ballot paper or asking for completed ballot papers, and Birmingham City Council has also introduced restrictions.
However Sir Albert said the parties should go further. He said: "It is crucial that the rules are not just strict but watertight. The protocols drawn up by both the Electoral Commission and the city council are not tough enough and do not go far enough.
"Labour already requires that its candidates and campaign workers sign up to an agreement that bans candidates and campaign workers from visiting postal voters in their home once the postal votes have been issued. We believe that such a ban is crucial to ensure that there is no interference, or risk of interference, with postal votes or postal voters."
He added: "If party workers are prevented from entering the homes of postal voters we can ensure that they do not touch someone else's ballot paper or solicit completed ballot papers.
"We have been applying this rule since last year and we believe the other parties should do the same."
