Labor's flagship Metro Rail project will deliver $1.10 worth of benefits of every $1 invested, the Andrews government has claimed.

Ahead of a push to secure federal funding for the $11 billion project, Premier Andrews told State Parliament "this project stacks up" using even the most conservative assumptions.

"This rigorous analysis shows a cost-benefit ratio on even the most conservative of methods of $1.10 back for every $1 invested," Mr Andrews told Parliament.

After factoring in so-called wider economic benefits an updated business case found the project would generate a return of $1.50 for every $1 invested.