Conservative MP Andrew Bowie said RBS should be ashamed.
Mr Bowie said customers who have already lost their branch in Stonehaven are unhappy with the replacement mobile service.
The West Aberdeenshire and Kincardine MP said Scottish Secretary David Mundell had taken their concerns to Theresa May and Philip Hammond.
“It’s 100% the wrong decision,” he said. “RBS should hang their heads in shame.
“David Mundell has spoken to the prime minister and the chancellor.
“I no longer have any RBS branches in the entirety of my constituency, which is the fifth largest in the country, because they have already closed Banchory, Stonehaven and Westhill.
“They have got a duty of care to their customers because this is another nail in the coffin for our rural communities so every north-east Conservative is on board with this campaign.”