United Workers Union members were due to down tools for two hours on Friday evening during one of the busiest trading times of the year, the Melbourne Cup Carnival.

But just a short time before the planned walkout, the union said a fresh offer would be put to members for a vote before any industrial action.

"Union members are holding meetings tonight to vote on next steps," the union said.

It comes after the union met with Crown in a bid to reach a last-minute deal.

The outcome of the informal vote will determine whether the strike will go ahead at a future date or if the secret offer will go to a formal vote in coming days, a delegate told AAP.

The union previously said they had met with Crown representatives for more than 15 bargaining meetings, failing to reach a compromise.

The union previously said 70 per cent of Crown's workforce, covered by the enterprise agreement, are in part-time or casual work, a rate almost twice as high as Australia's figure of 40 per cent.

Workers are seeking greater work stability, but Crown has said its staff appreciate flexibility.

Australian Associated Press