A campaign is being launched to help people with learning disabilities to vote in the next General Election.
It is estimated that 500,000 people in England with learning difficulties could vote but do not.
It is also estimated only about 16% of people with learning difficulties voted at the last election.
The United Response charity wants to raise that figure and has sent out what it calls a "toolkit" to all MPs, urging them use to jargon-free language.
The toolkit includes a CD explaining its message, which includes a request for MPs to use visual material where possible.
The charity is calling on all the major parties to produce manifestos in a form that is easy to understand for people with learning disabilities.
United Response chief executive Sue Sayer said its campaign had been running for the past three years.
"The campaign is really important because what people told us it that they find political information - I'm talking about manifestos and policy documents - really difficult to understand.
"And of course it's vital that they can understand what's being proposed because so many political decisions have a real impact on their lives.
"In a General Election things like health and social care, benefits, direct payments, they're all very important. And in a local election things like public transport come up time and time again."
Ms Sayer said the response from MPs to the charity's approach had been "fantastic".
She added: "They've been so enthusiastic, I've had hand-written letters from so many MPs saying how great it is to have this toolkit."
The report makes a series of recommendations, including calling for an increase in the number of people with learning disabilities voting in 2010, to at least 40%.
It also wants all main political parties to make the information about their policies and their candidates as accessible as possible ahead of the election, with easy read manifestos as a minimum.
The law says that anyone with a broad understanding of what voting is about, and the ability to choose between candidates is eligible to vote.
The voting figures for the general population for the last election was 61%.