London still faces a double bout of tube strikes this week as last-minute negotiations with management continue. But the messages from the unions have been mixed over the walkouts, which will see Underground workers and drivers strike on 25 and 27 August over the new Night Tube service.

The RMT has maintained that the discussions have been "constructive" since it called for the industrial action on 11 August. Steve Hedley, the assistant general secretary of the RMT, told LondonLive: "We are hopeful that management will see sense and come up with a package that will protect people's work/life balance and we will be able to avert these strikes."

The comments come before RMT's executive is expected to meet and give a final review of its strike action. TSSA has also told IBTimes UK that there has been no change in sentiment since the union said discussions had turned "progressive".

But there has been a marked shift in tone from the third union planning to walkout. Unite, which represents 400 electrical and maintenance technicians, linesmen and signallers on the London Underground (LU), warned that Underground bosses "have a lot of work to do" to convince the union to suspend its action after meetings on 21 August "weren't as productive" as Unite negotiators hoped for.

The remarks come after Hugh Roberts, a Unite negotiator, told IBTimes UK that he wanted to secure 2.5% pay hike for all Night Tube staff, instead of LU's proposed averaged 2% settlement. The union today said it was "still unhappy" with LU over the issue.

Unite on Night Tube

The parties are back at Acas today (24 August) and a spokesperson for the mitigation service told IBTimes UK that the unions and management were still in talks at the time of publication. LU has said it may be able to run some Tube services if the strike goes ahead.

"Staff on the bus network, DLR, London Overground, TfL Rail, tram, Emirates Air Line and river services will not be on strike. These services will operate as normal but they will be much busier than usual, especially during peak hours, between Tuesday 25 and Friday 28 August," a Transport for London (TfL) spokesperson said.

"Roads and National Rail services and terminals will also be much busier. We will run whatever Tube services we can on those four days, based on the staff that sign into their shifts. All customers are advised to allow more time for their journeys."

LU may be able to put on some services since Aslef, the union which represents a majority of Tube drivers, is not joining the strike action. A union source has repeatedly told IBTimes UK that its negotiators are "optimistic" that they can secure a deal from management over their work roster dispute. However, some of its members may not cross the RMT, TSSA and Unite picket lines.

The dispute threatens to undermine the Night Tube service, which was expected to roll-out on 12 September. But LU has maintained that the company is "operationally ready" for the launch date.