The Scottish government has called for a guaranteed minimum level of banking services after RBS proposed a series of branch closures.
RBS, which is 71 per cent taxpayer-owned after a government bailout at the height of the financial crisis a decade ago, has nearly 19 million customers across the United Kingdom and Ireland.
Rob MacGregor, Unite's national officer, described the cuts as "savage". Now serious questions need to be asked about whether these closures mark the end of branch network banking.
She said: 'We have no current plan to close any branches in Jersey.
"Banks must now give customers as much notice as possible when a branch is closing, and ensure they are made aware of the options they have locally to continue to access banking services".
The UK government said it did not interfere with commercial decisions.
It leaves RBS with just 744 branches in the UK.
Justifying the latest closures, the lender said more people are choosing to bank online or on mobile.
'Since 2014 the number of customers using our branches across the United Kingdom has fallen by 40 per cent and mobile transactions have increased by 73 per cent over the same period.
"Over 5 million customers now use our mobile banking app and one in five only bank with us digitally".
McEwan is also under pressure to cut costs to bolster the bank's profitability. For this year, however, it is still expected to chalk up a loss. The consumer body Which? calculated that across the industry 1,747 branches have been shut in three years.
He said the announcement of the closures would leave many communities without ready access to essential day-to-day banking services.
"We realise this is hard news for our colleagues and we are doing everything we can to support those affected".
"Nor do they care much about the elderly or those in poor health who can not travel any distance to their nearest branch".
The high street banks argue they have to compete with digital-only rivals such Atom and Monzo, which operate without a branch network.
Ahead of a meeting between the two governments expected on Monday, Mr Wheelhouse wrote: "I call on the United Kingdom government to establish and enforce a guaranteed minimum level of service provision for essential banking services, recognising the importance of continued access to banking for communities across Scotland, and across the United Kingdom".