Construction work has started on Cross River Rail, but the uncertainty surrounding the project, which has been discussed for more than a decade, looks set to continue.

Deputy Premier and Transport Minister Jackie Trad said the Labor government was progressing construction work, but that did not mean it was immune from the chopping block.

Deputy Premier Jackie Trad says Cross River Rail could still be scrapped, despite work beginning on Tuesday. Credit:Darren England/AAP

"After the next election, anyone can cancel any project they like," Ms Trad said.

"Construction companies are actually assembling their workforces as we speak and putting in their expressions of interest process.