The race is on. The union that represents Royal Mail workers has said they will ballot for a strike, and Royal Mail management says the most likely result of the vote is a decision to walk out.
But union rules say the earliest that could happen would be October 10th, and if they voted that way the company says they will look at their legal options.
Crucially though, the Government and the company believe they might be able to push the sale of the business through before then "in the coming weeks", potentially outmanoeuvring the union.
One of the biggest threats to a smooth sale would be disruptive industrial action. If the business and ministers can complete the deal before strike action that removes a major headache.
It is worth remembering that the union is not allowed to strike directly over the planned sell off. The ballot is over pay and conditions.