Only 16 per cent of people with learning disabilities are exercising their right to vote, it has been claimed, as a campaign is launched to make disabled people's votes count.
A report from United Response published today also found that at least half a million people who have the capacity to vote are not doing so.
The national disability charity is calling on political parties to do more to ensure that 2010 is the "most inclusive election in UK history".
Su Sayer, United Response's founder and chief executive, said: "People with learning disabilities are affected by decisions made at a national and local level in the same way as everyone else.
"Yet information about the democratic process is often presented in a way which is confusing and full of jargon. As a result, many people who would like to vote currently find themselves excluded."
The report follows three years of work funded by the Electoral Commission. It calls for voter turnout to increase to at least by 40 per cent.
All parties could publish their manifestoes in a format easy to understand for people with learning disabilities, it suggests.