Railway workers at UK's RMT union back further strikes in new ballot

May Day labour demonstration, in London

LONDON (Reuters) -Britain's RMT trade union said on Thursday railway workers had voted in favour of further strike action in a new ballot amid a long-running pay dispute with train operating companies.

"This sends a clear message to the employers that the huge anger amongst rail workers is very real and they need to recognise that fact, face reality and make improved proposals," RMT General Secretary Mick Lynch said.

Thousands of railway workers in Britain were already planning a strike on May 13 after the RMT rejected a new pay offer, the union said last week, escalating a campaign of strikes on the transport network since last summer.

The ballot result gives the RMT the mandate for six more months of strikes, but the union did not announce any fresh strike dates on Thursday.

The Rail Delivery Group, which represents the train companies, said the result was disappointing.

"We call on the RMT executive to quickly think again and put the deal - which offers job security guarantees and a pay rise of up to 13% - out to a democratic vote so that members can finally have their say," a spokesperson for the group said.

Separately, British train drivers also announced three days of strikes in May and June last week, in their own dispute with train companies.

Railway workers are among hundreds of thousands across Britain, including teachers, doctors, nurses and civil servants who are in pay disputes with their employers as inflation hovers around 40-year-highs of about 10%.

(Reporting by Sachin RavikumarEditing by Frances Kerry and Aurora Ellis)