Die Partei (The Party), whose policies include building a wall around Germany and putting Chancellor Angela Merkel on trial in a cage, said the ad was designed to represent its family policy.

Election rules require broadcasters to give parties advertising time to use as the parties see fit.

Merkel, with a comfortable lead in the polls over a so-far relatively toothless opposition, has opted for a bland campaign, short on specifics, that emphasizes business-as-usual.

Germany's top selling newspaper Bild called the advert, which aired at 10:30 p.m. after the main news, complete with steamy sound track of sighs and groans, a "climax" of the campaign. It said only three viewers had called national broadcaster ZDF to complain.

"Is anyone watching this political broadcast by Die Partei on ZDF and thinking what in God's name is this?" asked twitter user Katharina. Other users described it as the "best political broadcast ever".

Die Partei failed to meet the legal requirements to stand in the last federal election, but this time is fielding dozens of candidates - with next to no hope of getting any into parliament on September 22.

It described its advert, which ends with the slogan "Vote for The Party and you'll feel good", as having confused "dozens of pensioners".

Among its other policies is a plan to frack Environment Minister Peter Altmaier to release his "enormous energy resources".

(Reporting by Alexandra Hudson; Editing by Kevin Liffey)