He was elected to lead the Labour Group on Redbridge Council on 11 October 2011, with 15 of the 21 votes, beating Cllrs Stuart Bellwood and Andy Walker. This followed a vote of no confidence in the previous leader, Cllr Bob Littlewood. In the May 2014 borough elections Athwal led the Redbridge Labour Party to its first ever majority on the Council, gaining 11 seats to give Labour a total of 35 of the 63 seats, winning control from the Conservative-Liberal Democrat coalition. At the May 2018 borough elections, Athwal led the Labour Party to another victory, securing 51 of the 63 seats, increasing its majority by 15. This left the Conservative opposition with 12 councillors and the Liberal Democrats with none. In 2019 Athwal was elected Executive for Crime and Public Protection by the 33 leaders of London Councils. In 2019, Athwal was shortlisted to be the Labour parliamentary candidate for the constitutency of Ilford South. At the end of his campaign and hours before the final selection ballot, Labour suspended him due to allegations of sexual harassment. Athwal denied the allegations and called for due process. The timing of the suspension was publicly questioned by Wes Streeting since Sam Tarry, the other front-running candidate had close links to the Labour leader. After a second shortlisting process from which Athwal was excluded due to his suspension, Tarry was selected.
Athwal supports council housing, having built the first new council houses in 10 years in Redbridge after taking control of the council in 2014. He has a target to build 1000 new affordable homes in an effort to end homelessness in Redbridge.
Criticism
In 2019 a petition was signed by over 3000 residents after Athwal's majority group voted in favour of plans to build temporary accommodation on the sites of two green spaces in Hainault, in the north of the borough. The plans were introduced in 2018 as a response to Redbridge Council's statutory duty to house 2,300 homeless households, a national reduction in local authority funding, and a consensus that the available hostel accommodation was unsuitable for families. Plans for both sites included preserving and developing the play areas and remaining green space. Defending Athwal's decision to block some local residents on social media, the Deputy Leader of Redbridge Council referred to incidents of abusive language and invited blocked residents to contact Councillors through existing official channels. In October 2019 the leader of the Conservative opposition on Redbridge Council urged Athwal to stand down as leader until the matter of his disputed suspension from the Labour Party was resolved.