The Left party and anti-immigration Alternative for Germany look to be the strongest political forces in Berlin, as the German capital prepares for a consequential election in September.

One recent day in Berlin, a few hundred Pride demonstrators with rainbow flags rallied in eastern Marzahn district, a sweep of communist-era residential blocs that is a hotspot of far-right AfD support.

Far from the city's bohemian neighbourhoods with their hip clubs and trendy cafes -- areas which reliably vote for leftist and green parties -- this working-class district is Berlin's ground zero for a shift to the hard right.

In last year's national election, the anti-immigration, anti-Islam and Moscow-friendly Alternative for Germany (AfD) topped the polls with 31 percent in Marzahn, which is home to many Russian speakers.

Ahead of September polls in the city-state of Berlin, many progressive-leaning voters fear the AfD may again win big -- perhaps boosted by public anger over a deadly jihadist attack that targeted the city's main annual LGBTQ Pride event last weekend.