Fears about postal voting have prompted ministers to promise new safeguards to ensure public confidence in the system.
The government says the general election was safe and secure
A new offence of fraudulently applying for a postal vote, which could carry five years in jail, will be among laws promised in next week's Queen's speech.
Signatures and dates of birth would also be used to check postal votes.
Minister Lord Falconer said the general election had been safe but the system could be tightened. The Tories say he is just "tinkering".
The plans come after a judge said the postal voting system was "wide open to fraud" after a court case involving postal vote abuse in last year's local elections in Birmingham.
Police in several parts of the UK are investigating allegations of abuse of postal votes but so far there have been no formal challenges to any of last week's election results in the courts.
The rules were changed in 2000 so anybody could ask to vote by post.
After 15% voters asked for postal votes at the election, the main measures being proposed by the government are:
- Stopping political parties or community leaders receiving completed application forms for postal votes and then passing them on to election officials
- Increasing the time election administrators have to check postal voting applications by extending the deadline from six to 11 days before polling day
- Making it harder to forge ballot papers by using barcodes instead of the current serial numbers.
'Wait for police'
At a news conference, Constitutional Affairs Secretary Lord Falconer said: "The government believes the general election last week was safe and secure and produced a fair result which was fair and accurate."
He urged people to wait until investigations into allegations of voting fraud were complete before reaching conclusions.
Lord Falconer denies changes should have happened before the election
But he said were allegations and issues raised "which may have raised issues of public confidence" and the government wanted to introduced new laws at the "earliest opportunity".
The Electoral Commission watchdog has pressed for a system where each voter registers individually.
The government has stopped short of that measure. Instead, it is proposing one registration form per household which is signed by everyone registering to vote.
Lord Falconer said: "If we had separate registration forms for everybody would that reduce the number who register?"
He pointed to how the number of people on the electoral roll in Northern Ireland fell by 10% after the introduction of individual registration.
There is currently no offence of fraudulent applying for votes, although it is against the law actually to cast false votes.
Lord Falconer said: "What we are trying to do is recognise the postal voting is something that starts earlier and so try to make it a criminal offence at a much earlier time."
Ministers have decided that using some form of credit card-style system to prevent fraud, saying the measures have to be easy to use.
But signatures and date of birth may be used to check identification at polling stations.
Lord Falconer denied it would have been sensible to introduce the measures before the general election.
Conservative constitutional affairs spokesman Oliver Heald says the refusal to accept individual voter registration meant ministers were simply "tinkering at the edges".
Mr Heald said it was "shameful" that the government had not accepted in full the Electoral Commission's recommendations.
Liberal Democrat spokesman Lord Rennard said new safeguards were welcome but fraud could still be difficult to detect.
He argued the time had come to consider other ways of boosting turnout, including weekend voting.
"Many problems with the postal voting system may still remain, including the fact that many people will have to vote before they are in full possession of the facts that emerge in the last week of the campaign," he added.