"I've always taken an interest in good government and that stood out for me," Mr Rurawhe said.
"Open and transparent government is pretty important to me."
Mr Rurawhe's job was to get support for it and guide it through the select committee and three readings.
"(Select Committee) is where it is really scrutinised," he said.
The bill passed last week 109-12, with NZ First voting against it after voting for it at the first reading.
Mr Rurawhe said have "emphatic support" from the New Zealand Law Society, the New Zealand Law Commission and Ministry of Justice helped get the numbers.
"National voted against it at the first reading... but it's really uncommon for a Government to vote against the recommendation of its own ministry," he said.
"It was a very good experience guiding a bill through Parliament into law. It doesn't happen very often for a first term MP to get a piece of legislation through.
"I've got some other ideas, a bit more meaty ones to hopefully put into the ballot."