Watch: The moment Auckland's $1.4 billion Waterview Tunnel is officially opened by PM Bill English

Auckland's $1.4 billion Waterview Tunnel has been officially opened by the Prime Minister.

The new route is made up of twin tunnels which connect two motorways to the west and south of the city. Source: 1 NEWS

Bill English has unveiled a plaque in a ceremony at the tunnel entrance in Mt Roskill, assisted by the Finance and Infrastructure Minister Steven Joyce and Transport Minister Simon Bridges.

The twin three-lane 2400 metre tunnels join the Southwestern Motorway to the Northwestern Motorway.

With a simple snip of a ribbon by the PM today the major piece of transport infrastructure was opened. Source: 1 NEWS

Bill English, Steven Joyce and Simon Bridges at the opening of Auckland's Waterview Tunnel. Source: 1 NEWS

The Waterview Tunnel is now the longest in the country, taking the record from Christchurch's Lyttelton tunnel which is 1,970 metres long. 

Pupils from Western Springs College attended the officially opening of the $1.4 billion tunnel this morning. Source: 1 NEWS

The public will be able to walk and bike through the tunnels during special open days in the next two weeks.

The tunnels will open to traffic in early July.