Helen Clark and her press secretary made the decision to get the next possible flight out of Christchurch, the court heard. Picture / Herald file

Helen Clark and her press secretary made the decision to get the next possible flight out of Christchurch, the court heard. Picture / Herald file

The Prime Minister and her press secretary made the decision to get the next possible flight out of Christchurch, which in turn led to their high-speed journey through Canterbury, says the officer in charge of the speeding motorcade.

And another officer in the convoy, which reached up to 172km/h, said he was "brassed off" to discover later that the hasty trip had been arranged to get Helen Clark to a rugby test in Wellington - a journey she had told him was "heroic".

The diplomatic protection squad (DPS) member who was in charge of the motorcade told the Timaru District Court yesterday he was told by press secretary David Lewis that they should aim to reach a flight that would require the motorcade to exceed the speed limit.

The DPS officer, whose name is suppressed, said he learned about 2.30pm that Helen Clark's original flight from Timaru had been cancelled.

Senior Constable Clint Vallender, second-in-charge of the motorcade, handed him details of two flights available from Christchurch at 4.50pm and 5.40pm.

"The Prime Minister was still engaged in conversation, so I spoke to David Lewis and informed him of the situation and advised him of the two flights and of the drive time to Christchurch," the DPS officer told the court.

"He then spoke to the Prime Minister and after a brief conversation, which I was not privy to, advised me that they needed to make the 16.50 hours flight."

The DPS officer said he organised a marked car to lead the motorcade.

"I was reliant on the local knowledge of Senior Constable Vallender and the lead vehicle to determine the speed of the motorcade as to make the 16.50 hours flight," the officer said.

"On the occasions I did glance at the speedometer I observed that we were travelling at approximately 130km/h, but this was mainly on straight roads and passing lanes."

Mr Vallender's evidence was also heard yesterday. He admitted being "brassed off" on learning that Helen Clark had needed to catch the flight to get to the Bledisloe Cup test that evening.

He said the Prime Minister had earlier thanked police for a "heroic" drive to Christchurch.

Mr Vallender, the DPS officer, and four other men are on trial on driving charges arising from the motorcade on July 17 last year.