Germany's equality czar has spoken about removing words such as "fatherland" and "brotherly" from the country's national anthem.

Kristin Rose-Moehring, equality commissioner since 2001, proposed eliminating male references in the anthem in a letter to staff at Germany's family ministry ahead of International Women's Day on March 8, Reuters reported.

Germany should replace "Vaterland", meaning fatherland, with "Heimatland," meaning homeland, she wrote.

"Why don't we make our national anthem ... gender sensitive... It wouldn't hurt, would it? And it fits with the new federal ministry for interior, construction and homeland."

The proposal came hours before Germany's centre-left Social Democrats (SPD) announced that 66% of its members backed a re-run of the coalition with Chancellor Angela Merkel's conservatives that has ruled Germany since 2013.

Merkel commented on the debate on Monday, saying she was "very satisfied" with the current lyrics, BBC reported.

Poet August Heinrich Hoffmann von Fallersleben wrote Deutschlandlied, or Song of Germany, in 1841. Parts of it have formed the national anthem since 1922.

However, only the third stanza has been used since 1990, when Germany became the modern federal republic.