We will mourn together - Brownlee

Dust cloud over Christchurch City, moments after the 6.3 magnitude earthquake struck. Photo / Supplied

A city will acknowledge its shared suffering in today's national memorial to the Christchurch earthquake victims, Earthquake Recovery Minister Gerry Brownlee says.

Tens of thousands of people are expected to gather to pay their respects at the National Memorial Service in Hagley Park at 12.30pm.

It will be led by the dean of the earthquake-damaged Christchurch Cathedral, Reverend Peter Beck and will feature performances by artists Dave Dobbyn, Dame Malvina Major and Hayley Westenra.

Prince William, Prime Minister John Key, Governor-General Sir Anand Satyanand and Christchurch Mayor Bob Parker will pay tribute to the families who have lost loved ones.

A two-minute silence will be held at 12.51pm to mark the moment the earthquake struck on February 22.

The service will be a chance for Christchurch residents to unite in grief and to look towards recovery, Mr Brownlee said.

There have been few opportunities for people to stop and mourn as they work to get on with life in the wake of the February 22 earthquake, he said.

"There's few people who weren't affected by the earthquake in this city.

"There's shock and grief. You've got hundreds of suffered injuries from the extreme to the minor, tens of thousands whose lives that were turned upside down. Some will never be the same.

"For most there's a chance to park up these feelings of grief into a day where everyone acknowledges everyone is suffering. We're all in this together."

He defended the memorial against criticism it came too soon after the February 22 earthquake.

"There will always be people who question a particular day or a particular way of doing something.

"It is right. It feels right to me."

Officials have urged residents to walk, bike or take buses to the service to avoid traffic gridlock.

Free buses will be running from two key stops on Bealey Avenue and Hagley Avenue and limited bike racks will be available.

Car parking is being organised at two car parks in Hagley Park.

Other events:

Auckland

A service will be held at the Cenotaph at the Auckland Domain at 7pm.

Those who attend the hour-long service will be encouraged to light candles and lay flowers after the ceremony.

Mayor Len Brown says it is important people take time to reflect on Christchurch's "loss, spirit, courage and resilience as New Zealand works together with the people of Canterbury in their time of need."

Free buses will run from Customs Street outside the Mercure Hotel in the CBD every 10 minutes from 5.30pm until 7pm.

Wellington

The National Memorial Service will be screened live in the TSB Bank Arena at Queens Wharf. Doors open at 12pm.

Councillor Ian McKinnon - who will be representing the council at the screening as Mayor Celia Wade-Brown is in Christchurch - says Wellingtonians have shown real empathy for the people of Christchurch.

"We also know there are now a number of Christchurch families in Wellington and this will enable them to 'stand as one' at this difficult time."

A small space will also be provided in Wellington Central Library for people to watch the broadcast.

Dunedin

A memorial service will be held at Knox Church, on George St in Dunedin from 7pm.