He also called for a “more diverse” pro-EU drive.
“This campaign, if it should fall upon us, for a public vote, it needs to have less Tories, less men, less Londoners, more northerners, more women, more diversity and more of the left,” he said.
Labour’s current position is to seek a general election and, if it fails, to keep “all options” on the table, meaning support for a second poll is not a done deal.
Lewis said he did not want to get sacked by going off-script and hinted the second referendum campaign could pave the way for Labour victory at the general election – due to take place in 2022 – by demanding left-behind towns get “a new deal”.
“It isn’t just about remain and reform of the EU, it is about reform of the UK and about the new kind of deal we will offer to this country under the next Labour Government and what difference it will make to their communities,” he said.
De Cordova, meanwhile, also backed a second referendum and said she was at the event to “show solidarity”.
“What we are facing now is a right-wing, racist Brexit from this Tory government and we cannot in any way stand in line with that,” the shadow minister for disabled people said. “We really have to reject that.