Security around Parliament is being beefed up following the Budget day incident.
The building was briefly placed in lockdown on May 26 after a suspicious farm ute with a tank on the back was driven onto the forecourt, prompting a full-scale response from security and emergency services.
People were prevented from leaving or entering Parliament's grounds and nearby streets were cordoned off.
Finance Minister Bill English was late for a media conference ahead of his budget speech.
A man was arrested.
Prime Minister John Key says that was far more worrying than the fact that one of his security officers left a loaded gun in a bathroom in parliament on Thursday last week.
"If the truck had been packed with a fertiliser bomb or something, then that would have represented a real risk to people who were close to it," he said today.
He said Parliamentary services have since been looking at security issues.
"You've seen the bollards they are potentially putting up at the back, and I suspect there might be other changes," he told reporters.