The Pentagon has begun urging US states to organise electronic ballots for more than 250,000 US troops who will be serving abroad when voters go to the polls in November to elect a new president and commander-in-chief of all American forces.

While most servicemen and women can communicate with their families via the internet from some of the remotest outposts of Iraq and Afghanistan or from naval carrier battlegroups in mid-Pacific, most are still confined to registering their political preferences by surface mail.

Thousands complained after the 2000 election that their ballot papers failed to arrive in time to be counted.

Of the 50 US states, only seven - Colorado, Indiana, Mississippi, Missouri, Montana, North Dakota and South Carolina - allow serving military voters to return their selection online.

The wars in Iraq and Afghanistan are seen this year as key presidential campaigning issues, making it more urgent than ever that those fighting them should be able to influence events.

The Federal Voting Assistance Programme said yesterday that voting participation by US troops was 79% in 2004, compared with 64% for the civilian population, making military votes a powerful block.