Dozens of schools in south London will be impacted by strike action on Friday, with more than 1,000 school support staff to stage a protest over pay.

Members of the GMB union employed in Merton and Greenwich are holding a rally and march in Westminster on October 9, having previously walked out in May.

The dispute centres around London weighting payments, with the staff arguing that teachers in their schools receive the inner London rate but they are paid the lower outer London rate, a difference of up to £1,400 a year.

Teaching assistants and other support staff will stage a rally in Old Palace Yard before marching to the Department for Education to take their message to senior politicians.

Merton Council has confirmed that 28 schools in the borough will be affected by the strike action.

A statement on the council website reads: “We are disappointed that this further strike action is planned and are urging the GMB to call off the action to minimise disruption to children and families while work continues to find a lasting resolution.

“In the meantime, the council is working closely with affected schools to minimise disruption to children and families.”

The council says that it recognises the “enormously important contribution” that school support staff make to children’s education.

While it supports the case for fair pay, Merton Council says it cannot legally fund the increase at local level, nor endorse a one-off payment which would create knock-on consequences for other council services and residents.

Greenwich Council have reported that three schools in the area have alerted them to closures or partial closures on Friday.

Thomas Tallis School in Kidbrooke will be open to years 11 and 13 only, while Christ Church C of E Primary School in Shooters Hill will only be open to Years 1, 2, 3 and 6.

Invicta Primary School in Blackheath will be fully closed due to the strike action.

Nadine Houghton, GMB Regional Secretary said: “This is an historic underpayment that our members are owed.

“As a dedicated school support staff union, it is non-negotiable to us that our members be treated equally with teachers in the self-same schools and receive Inner London Weighting.

“Since both local authorities are pleading poverty and burying their heads in the sand, our members have voted not only to take action but also to take their message to parliament.

“If the councils hadn’t been kicking the can down the road all summer, perhaps this second day of action might not have been necessary.

“If parents at any of the affected schools are concerned about the schools remaining open or about the safety of their children, they should contact school management, the councils directly or their local councillors and MPs.”