“With my aims fulfilled, I have decided to step back from the race to focus on my role on the NEC,” he explained.
Mr Lansman, whose group was instrumental in propelling Mr Corbyn to the party leadership, said a number of party members had informed him they were planning to stand for the post.
Ordinary party members must be encouraged to step forward and take responsibility, he said.
Focusing on the NEC, he said he would “work with members and affiliates to replace the old top-down model with modern, open, and transparent, pluralist, participative democracy”.
The Labour leadership is believed to support Jennie Formby, the former political director of the Unite trade union, as the candidate to succeed Mr McNicol and had feared a split in the left vote if Mr Lansman had stood.
