UPDATE 2-UK rules out ditching 'triple lock' pledge on state pension increases

(Recasts with PM's spokesman comments)

LONDON, June 21 (Reuters) - Britain is not planning to ditch its promise to protect annual state pension increases with a so-called 'triple lock', Prime Minister Boris Johnson's spokesman said on Monday.

British newspapers have reported that the government was looking at suspending the promise to increase pensions by whichever is higher of consumer price inflation, average earnings growth, or 2.5%. They said it could help pay for the cost of the government's COVID-19 response.

"We are committed to the triple lock," the spokesman said, when asked about the reports.

Due partly to distortions from the coronavirus pandemic, annual wages in the three months to April grew by an annual 5.6% - creating an extra 4 billion pound ($5.5 billion) annual cost for future pensions.

The promise to maintain the system for increasing pensions was in the Conservative government's manifesto of pledges ahead of the 2019 election.

The spokesman also ruled out income tax rises. "There was a promise made at the election that we would not raise rates of income tax and when we stand by that," he said. (Reporting by Guy Faulconbridge; writing by Michael Holden and William James; editing by Alistair Smout)