Prime Minister John Key's inaugural ride on Christchurch's new tram loop had a minor hiccup when the tram's trolley pole detached from the overhead line.

The tram, driven by Key, lost power and came to a standstill.

Tram staff scrambled to place the trolley pole back on the line and it then operated normally for a trip up and down Cashel St mall.

Stacy Squires Prime Minister John Key's ride on the Christchurch tram did not go smoothly.

Key was in Christchurch today for the opening ceremony of the Cricket World Cup, but attended the opening of the tram loop's new extension this morning.

WATCH: A sneak peek at the World Cup opening ceremony

The new electric tram loop extends the existing tramway along Oxford Tce and through Cashel Mall and parts of High St.

Key said more tourist ventures re-opening showed "Christchurch is open for business".

"I sometimes get a hard time from the Greens about never taking public transport, so next time they ask when was I last on a tram or a train, I'll say 12 February 2015. So that will help that parliamentary question," he said.

The council decided to lay new tracks in Cashel and High streets between 2007 and 2009 but the plans were derailed by the February 2011 earthquake.

Last year the council committed $1.875 million to finish the loop, including completing tracks behind Christ Church Cathedral, creating a crossover at the intersection of High and Manchester streets, and completing the erection of overhead poles, arms and wires.