Elections minister Harriet Harman visited a mosque in the Old Kent Road on Friday to speak about voter registration and the right to vote.
New figures show that an estimated 60,000 London Muslims have no right to vote. A London-wide voter registration drive is getting under way to tackle under-registration among Londoners in time for the local authority elections in May.
Ms Harman visited the Old Kent Road Mosque on Friday afternoon and is writing to all Imams in London mosques asking them to urge London's Muslims to register to vote.
Londoners have until 13 March to register in time for the local authority elections in May this year.
Ms Harman said: "Many Muslims cannot vote as they are not registered to vote.
"We are proud of our democracy. But it is not working properly when people are denied the vote because they are not on the register.
"The Government is determined to improve our democracy and tackle inequality. We are taking action to tackle the problem of inequality in voter registration.
"I am therefore asking London's mosques to make voter registration forms available to their congregations.
"Democracy only works if everyone votes. We need as full an electoral register as possible so that everyone has the chance of having their say."
• Earlier this month Ms Harman visited Southwark College in The Cut as part of a drive to encourage students to join the electoral register
• Find out how to register to vote if you live in Southwark or Lambeth.