OCCUPY Melbourne may ruin the wedding plans of couples wanting to celebrate their special day in Treasury Gardens.

Several couples are planning to hold ceremonies, post-wedding celebrations and picture opportunities in the gardens today, where protesters plan to establish a tent city.

Occupy Melbourne said couples using the park for ceremonies and photographs would have to pose alongside protesters.

The group plans to occupy more than two-thirds of the gardens today, erecting a tent city it hopes will become home to thousands.

Police will be monitoring the occupation today, with fears that it will turn into another powder keg, as protesters have received training on how to deal with the effects of capsicum spray and tear gas.

Detectives are also investigating whether Occupy Melbourne protesters on bail were key players in last week's City Square confrontation with 400 police.

Lord Mayor Robert Doyle said protesters should respect the rights of couples wanting to use the park for ceremonies and photographs. "A right to protest is not an unlimited right without regard to whatever else is happening," he said.

Lalor couple Alex Micevski, 42, and Emilija Nanevski, 30, will tie the knot at the Old Treasury Registry at noon today, with photographs to follow in the gardens.

But protesters plan to march to Treasury Gardens from the State Library at the same time.

"You don't really want to see a protest when you're getting married, particularly when you've got a picturesque garden like the old Treasury Garden there," Mr Micevski said.

He had hoped they would be able to get their photos done in the gardens but if the protest was "in full swing and they're being vocal", they would have to move to the gardens near Parliament House.

Occupy Melbourne spokesman Nick Carson said that wedding parties would have to share the gardens with protesters.

"It's up to them where they take their photographs. If they wanted to have them in front of the general assembly, that's fine," he said.

"This occupation could be here for years to come, or decades to come."

The group still believes the City Square eviction was legally "highly dubious".

Originally published as Rally takes the cake for wedding