Upper House Liberal MP Shayne Mallard welcomed the completion of the upgrades while having a swipe at Labor over the issue.

"Blue Mountains commuters are to be congratulated for working co-operatively as the rail line and some stations have been upgraded to meet the same rail standards as the remaining Sydney network," he said.

"Contrary to the fake news spread by Labor's local member [Trish Doyle], it should be remembered that the existing trains are over 30 years old and destined for the rail museums.

"Labor failed to upgrade the trains during their 16 wasted years in office. Whilst they did partially upgrade the trains to Wollongong and Newcastle, they sadly put Blue Mountains commuters in the too hard basket.

"Only the NSW Liberal government has invested millions in upgrading the lines, tunnels and stations to allow the new state of art intercity fleet to service our community and the whole intercity network," said Mr Mallard.

But Blue Mountains MP Trish Doyle reiterated her previous fears about the "new, shiny off-the shelf trains from Korea".

"I am concerned that many safety issues have been raised by rail workers, by drivers and guards particularly - and have not been addressed. There is no guard compartment!" she said.

"It might be good being able to charge your phone [on the new trains] but safety must be a priority, particularly for long hauls."

The new train fleet has also come under heavy criticism in the Blue Mountains for not having reversible seating or a vestibule area to keep out cold air in winter.

Blue Mountains Gazette Facebook followers reiterated these concerns in comments on social media last week.

"Dread the fixed, hard seats enough to buy a car," wrote Pan Keshvardoust.

The fleet has already started testing and training on the Sydney network and is expected to be testing the lines to Katoomba in the coming months.