The Labour Party has one advantage over its main General Election rivals - according to a survey by AbilityNet, it runs the most accessible website.
The governing party was praised in the charity's seventh quarterly State of the eNation survey, which awarded its first four-star rating to the site.
The Conservative Party and the SNP achieved a rare three-star grading, which indicates compliance with access legislation in the Disability Discrimination Act. But the charity branded the Liberal Democrats' site illegal, saying it failed to satisfy basic accessibility criteria and giving it only two stars.
Robin Christopherson, the charity's web consultancy manager, who is blind, said: "For the millions of people with a disability or dyslexia, the presence online of party information may fulfil a crucial role in their decision-making."
The LibDems pledged to improve accessibility standards when faced with the findings, but other parties given two stars, including Plaid Cymru, Sinn Fein and UKIP, failed to respond.
Christopherson added: "The Labour Party is to be congratulated for setting a precedent for its rivals. We look forward to the Government's Digital Strategy promoting best practice in future website development."