The decision was announced earlier this month by Transport Minister Gladys Berejiklian, whose electorate covers Artarmon.

It has caused controversy with some saying it had "jumped the queue", claims Mrs Berejiklian has not directly responded to.

The government will also be installing lifts at Arncliffe and Marrickville stations.

In Parliament on Tuesday, Ms Hay claimed Mrs Berejiklian had reneged on an election promise to build lifts at Unanderra.

"Prior to the last election, the Minister for Transport stated that she would ensure 'public transport needs are met and improved' citing 'the need for an easy access upgrade at the Unanderra station'," Ms Hay said.

"With no progress over the past three years, it is obvious that this government will say anything to get elected."

Ms Hay also raised questions over the decision to install lifts at Artarmon, a station in Mrs Berejiklian's electorate of Willoughby.

"Now as a clear means of political point scoring, the Transport Minister has again failed to come clean about her plans to fast-track the installation of lifts at other stations in Sydney including one in her own North Shore electorate, pushing Unanderra further down the list," Ms Hay said.

"I am curious as to how a station in the minister's own electorate has made it to the top of the waiting list, and will be getting easy access lifts ahead of Unanderra.

"This minister needs to explain this blatant reneging on election commitments."