An openly gay lawyer has announced he would stand in Tunisia's presidential elections, a first for the Arab world.

Mounir Baatour's candidacy marks "a first which will without doubt be a benchmark in history", his Liberal Party said.

Mr Baatour, the party's chief and a lawyer at the Court of Cassation, presents himself as a defender of LGBTIQ rights.

But ahead of his announcement, a petition signed by 18 groups who campaign for those rights warned his candidacy would represent a "danger" for their communities.

Mounir Baatour was jailed for three months in 2013 for sexual relations with a 17-year-old student, something he denies.

Having a criminal record does not automatically ban Tunisians from standing in elections.

"The fact that I'm gay doesn't change anything. It's a candidacy like all the others," Mr Baatour said.

"I have an economic, social, cultural and educational programme for everything that affects Tunisians in their daily lives," he added.

Presidential hopefuls have until Friday to submit their candidacy, ahead of 15 September polls.