At the 2006 general election, Lui was elected to Parliament as a Member of the People's Action Party (PAP) team in the Tanjong Pagar Group Representation Constituency (GRC).
He was re-elected to Parliament at the 2011 General Election, this time in Moulmein–Kallang GRC.

Lui was appointed a Minister of State at the Ministry of Education on 30 May 2006.
On 1 April 2008, he became the Senior Minister of State at the Ministry of Education and the Ministry of Information, Communications and the Arts.
He was made the Acting Minister for Information, Communications and the Arts on 1 April 2009, and became a full member of the Cabinet in 2010 and was appointed Second Minister for Transport assisting Raymond Lim.

After the 2011 general election, Lui was appointed the Minister for Transport and Second Minister for Foreign Affairs.
He relinquished his portfolio in the Ministry of Foreign Affairs on 1 August 2012, and remains the Minister for Transport.

During his tenure as Minister for Transport, Lui defended the privatization of the public transport system, explaining that if public transport were to be nationalised, operators would be dependent on government funding as well as operate on a cost recovery basis.
This he added, would not spur them to lower transport costs.
Lui is adamant that the companies remain financially viable by approving yearly fare hikes.
At the 2006 general election, Lui was elected to Parliament as a Member of the People's Action Party (PAP) team in the Tanjong Pagar Group Representation Constituency (GRC). He was re-elected to Parliament at the 2011 General Election, this time in Moulmein–Kallang GRC.
Lui was appointed a Minister of State at the Ministry of Education on 30 May 2006. On 1 April 2008, he became the Senior Minister of State at the Ministry of Education and the Ministry of Information, Communications and the Arts. He was made the Acting Minister for Information, Communications and the Arts on 1 April 2009, and became a full member of the Cabinet in 2010 and was appointed Second Minister for Transport assisting Raymond Lim.
After the 2011 general election, Lui was appointed the Minister for Transport and Second Minister for Foreign Affairs. He relinquished his portfolio in the Ministry of Foreign Affairs on 1 August 2012, and remains the Minister for Transport.
During his tenure as Minister for Transport, Lui defended the privatization of the public transport system, explaining that if public transport were to be nationalised, operators would be dependent on government funding as well as operate on a cost recovery basis. This he added, would not spur them to lower transport costs. Lui is adamant that the companies remain financially viable by approving yearly fare hikes.
Lui Tuck Yew