Sweden's Social Democratic party, which leads a minority government, on Tuesday pledged to ban all religious charter schools to tackle segregation in the country which took in a record number of asylum seekers in recent years.

"We have to knock down segregation to keep Sweden together...school segregation must therefore also be broken down," Ardalan Shekarabi, a leading member of the Social Democrats, told a news conference in Stockholm.

The proposal is not backed by the majority of the parliament at this stage, as most of the charter schools are Christian.

The announcement is largely seen as a symbolic move six months ahead of the September 9 general election.

Shekarabi, who is the minister for public administration, said his party, the nation's largest, hopes to gain voters' support on the issue in the poll.

Out of the 71 primary and upper secondary (for students aged 16 to 18) religious charter schools -- five percent of all charter schools in Sweden -- 59 are Christian, 11 are Muslim and one is Jewish.

They receive state funding but operate independently.

A Muslim primary charter school in Stockholm triggered outrage last year for separating boys and girls on a bus and during sports lessons.

"Teachers and pedagogues should be in charge of a Swedish school, not priests and imams," Shekarabi said.

Omar Abu Helal, principal at an Islamic charter school in southern Sweden, slammed the proposal as "a violation of the European Convention of Human Rights" and "the freedom of religion".

The expected main issues during the election campaign are health care, education and immigration in Sweden which has registered around 400,000 asylum requests since 2012, or one for every 25 inhabitants, a record in Europe.