MPs could get an extra £10,000 a year to help them keep in touch with constituents in a planned shake-up of the commons allowances system.
"We do have to keep up with the times," Jack Straw told fellow MPs
Commons leader Jack Straw said a change to the expenses policy was needed as MPs now received 300 letters a week.
But in a debate on reform, Labour MP Chris Mullins voiced fears the money might be spent on "vanity publishing" rather than proper correspondence.
And Lib Dem Jo Swinson said as there were 646 MPs the scheme could cost £6m.
The money would be in addition to an annual sum of approximately £7,000 which each MP could put towards envelopes with pre-paid stamps, a senior Commons source told the BBC.
But Mr Straw replied that he "didn't believe for a second" that the cost would be as high as Ms Swinson claimed.
But he conceded: "We do have to keep up with the times.
"There is a demand, not for a report with glossy photographs of a sitting MP but actually describing in some detail what I have been doing."
Confusion surrounds the present rules, with suggestions some MPs may be using their allowances to send political brochures, rather than straightforward communications on constituency matters.
Ms Swinson countered there had been a "failure" to enforce the current postal rules, resulting in the need to "combat some of the very extravagant claims by a small minority of members".
And Conservative MP Julie Kirkbride maintained this theme, branding the proposed allowance an exercise in "save our seats for the Labour Party".
"Many of our constituents would rather we were more considerate of taxpayers' money than to send them a communication they haven't asked for, and would probably put straight in the bin."
If MPs vote for the allowance, the Members Estimate Committee will prepare detailed proposals for further consideration.
The debate comes a week after it was revealed that MPs claimed more than £86m in allowances in the year to 31 March.