The ACT Legislative Assembly has passed a motion accusing Liberal MLA Zed Seselja of betraying Tuggeranong voters by moving into federal politics.

The former Canberra Liberals leader is running for the Senate, after being re-elected to the Assembly last October.

Today Mr Seselja moved a motion calling for better services in the Lanyon Valley.

But Labor MLA Joy Burch made an amendment criticising Mr Seselja, which passed with the support of the Greens.

"Mr Seselja neglected to mention, as he promised the world to the people of Lanyon, that he would stick around for as long as it took him to find something better," she said.

The Opposition labelled the motion a 'grubby attack' and Mr Seselja hit back.

"If I am honoured to be elected to another place, I will serve the people of Tuggeranong, I will serve the people of Gungahlin, I will serve all the communities of Canberra and the entire ACT," he said.