NSW postal workers today agreed to return to work as a gesture of goodwill to the public to try to clear the backlog of mail before Christmas.

They had walked off the job earlier, along with other staff nationally, as part of a campaign for a new workplace agreement that protects penalty shifts and pay, and improves workplace safety.

But, while the other states remain on strike, several hundred angry NSW workers agreed at a meeting in Strawberry Hills, Sydney, to return to work at the next ordinary shift.

It's the second strike in a week, after 20,000 workers walked off the job on Wednesday, December 16, disrupting mail services nationwide.

Police closed Cleveland Street as the workers tried to march on Australia Post headquarters, carrying banners and balloons.

