Research by UpMyStreet.com reveals only 18% of Labour MPs have made their addresses public, despite the party's support for electronic debate and commerce.

The Lib Dems are big online

In contrast, 41 out of the Liberal Democrats' 46 MPs have made their e-mail addresses available to the public.

A party spokesman said: "A lot of our MPs are very aware of new technology. Paddy Ashdown himself is very keen on e-mail - he's constantly on e-mail."

But Ian Charles Stewart, chairman of Aztec Internet, the company behind UpMyStreet.com, said the research showed "an appalling lack of e-mail contactability among MPs".

He said: "It is an irony that the Labour Party - which is the most vocal supporter of the online economy for the next millennium - is the worst offender.

"While politicians might be using e-mail for internal communications, they are keeping themselves needlessly remote from their constituents by not having a publicly accessible address.

"The Internet provides a perfect environment for a virtual surgery."

E-mail provides the perfect vehicle for virtual MPs' surgeries, UpMyStreet suggests

The official opposition did not rate much better in the survey of online openness.

Only 22% (35 out of 164) of Conservative MPs can be easily contacted via e-mail.

The UpMyStreet site allows users to find information on their area, such as ambulance response rates, chemical releases and hospital waiting lists.

But when it decided to add political information to its lists it encountered problems.

No-one at the Labour party's Millbank headquarters could immediately explain their MPs apparent resistance to e-mail.

But Paul Flynn, a Labour backbencher who is in the process of setting up his own extensive Website, said he thought the party was missing out.

"It's the communication of the future," he said. "It's by far the most effective way of communicating with constituents."

And in the office of the Lib Dem leader they are discovering considerable benefits from online communication.

Researcher Michael Hines said: "We get about 15 to 20 a day, of which a proportion will be junk mail. It follows a similar pattern to the rest of the mail we receive and reflects the major issues of the day.

"Quite a lot of e-mails come from America - people who've seen Paddy on C-Span and want signed photos."

Moving with the times: Edward Heath has e-mail and a pager

He said the party had an online conferencing facility, which allows internal discussions and communications.

"Generally the party's got quite into online and there's been a rolling momentum. Paddy's got a little palmtop that he can plug into his mobile phone and communicate with us when he is on the road - his enthusiasms has made a difference."

However, in Sir Edward Heath's office - another MP whose e-mail address can easily be found - people were less enthusiastic.