PM breaks ground on Sydney's WestConnex

Work on fixing up a highway bottleneck in southwestern Sydney is set to start 18 months early.

Prime Minister Tony Abbott and Premier Mike Baird attended a sod-turning ceremony on Monday that marks the beginning of the second stage of Sydney's WestConnex road upgrade which involves the widening and extending the M5 motorway.

"WestConnex will create 10,000 jobs, it will cut up to 40 minutes off literally hundreds of thousands of people's daily travel time," Mr Abbott said in Beverly Hills.

The WestConnex project is part-funded by the Commonwealth, which has given the state $1.5 billion and a $2 billion concessional loan.

NSW Roads Minister Duncan Gay said that money had allowed work on the $130 million King Georges Road Interchange Upgrade to be brought forward.

"We will have finished it before we were meant to start it and that's because of that $2 billion loan that you gave us," NSW Roads Minister Duncan Gay said.

"We wouldn't have been starting this project for another 18 months. This is one of Sydney's worst pinch points."

WestConnex is designed to link up Sydney's west and southwest to the city, airport and ports precincts.