Labour leader Jacinda Ardern has promised to fast-track Christchurch's rebuild with a $300 million capital injection if her party comes to power after the September elections.

“This fund will be subject to compelling business cases showing strong potential for economic, environmental or social returns to the city. We’ll negotiate a global settlement with the Christchurch City Council, settling the long-term ownership, opportunities and funding for the anchor projects,” Ms Ardern said at the launch of Labour's plan for Canterbury on Sunday in Christchurch.

This will provide the certainty that residents, developers and investors need, she added.

Under her leadership, a Labour government will also commit an additional $100 million for multi-modal public transport for Greater Christchurch, including commuter rail from Rolleston to the Garden City's CBD, as well as restore full democracy to Environment Canterbury.

Noting the importance of mental wellbeing in post-earthquake Christchurch, her government will fund an extra eighty mental health professionals across primary and intermediate schools in Christchurch, and a two-year pilot programme of mental health teams to work throughout the health sector, she said.

Importantly, a University of Canterbury study whose findings were released last week has found that 80 per cent (four in five) primary school-goers in Christchurch are exhibiting symptoms of post-traumatic stress disorder (PTSD).

The Labour leader also promised to establish an arbitration tribunal to fast track the resolution of insurance issues, as well as provide extra funding for the Residential Advisory Service, if she becomes the next Prime Minister of New Zealand.