She was not appointed a minister in the Fifth Labour Government, which held power in Yates' final three terms, but was highly active as a legislator with five private member's bills—mostly related to women's rights—considered by Parliament during her career.
She held three select committee chairs: government administration from 1999 to 2005; foreign affairs, defence and trade from 2005 to 2008; and education and science in 2008.
[12] Yates said she came to the issue from a "radical feminist" perspective;[13] while speaking on the bill in Parliament, she suggested the bill could do away with sexual intercourse for reproductive, but not recreational, purposes and that New Zealand needed "at most eight fit human males with high sperm counts" to replenish its population.
In 1999, she proposed amendments to government legislation that would have required all alcohol containers to carry warning labels including "Women should not drink liquor during pregnancy because of the risk of birth defects."
[10][21] In her second term, she inherited the Local Elections (Single Transferable Vote Option) Bill from her defeated colleague Richard Northey.
The bill proposed letting local authorities choose the single transferable vote electoral system for their elections.
In the final parliament elected under the first-past-the-post voting system, the bill had been sent to the electoral reform subcommittee, which unanimously recommended its passage.
[30] As chair of the government administration committee, she led inquiries into the leaky building crisis and hate speech in New Zealand.
[31][32][33] She voted in favour of civil union legislation in 2004[34] and retaining or restoring an alcohol purchase age of 20 years in 1999 and 2006.
"[38] Yates contested Hamilton East for the fifth time in the 2005 election, but lost the seat to new National candidate David Bennett by a significant 5,298 votes.
In August 2007, she announced that she would retire from Parliament by the end of the year in order to stand for the Hamilton City Council.