Supporters of Labour MP Louisa Wall's bill at Parliament. Photo / New Zealand Herald

A 1000-strong march in support of same-sex marriage has reached Parliament steps.

The group was met by MPs from Labour, National, Greens, Maori and Mana after marching from Civic Square.

The bill's sponsor Labour MP Louisa Wall was introduced as "New Zealand's own Rosa Parks".

She told the crowd that the discrimination in New Zealand's marriage laws needed to be amended.

She also asked church leaders and other opponents to be tolerant as the bill was debated.

"Please do not fear what this bill will do," she said.

A group of 20 opponents of the bill met the march, holding placards that read '"Don't break the definition of marriage".

The bill is expected to pass its first reading comfortably this evening.