EMBATTLED Royal Bank of Scotland chief executive Stephen Hester has revealed the extent of the pressure he faced over his near-£1 million bonus and admitted his view on whether he will stay on to turn the institution around "varies from moment to moment".

Mr Hester, who yesterday said he had briefly considered resigning over the row about the pay award – which he waived – spoke out as Labour and the Tories became embroiled in a new dispute over bonuses.

Mr Hester told The Herald the focus should be on RBS, on customers, and on working to return the £45 billion of public funds injected following the Edinburgh-based bank's near-collapse in 2008.

He said that "losing focus" on these things was not to the advantage of the UK and not to the benefit of RBS or himself.

But his remarks will fail to quell fears among some institutional investors that he might walk away from the 82%-taxpayer-owned bank.

Asked if he intended to stay on until the company's turn- around was completed, Mr Hester replied: "Obviously, I may not have the luxury of decision-making on that, and my own decision-making varies from moment to moment...

"If I think RBS can win and I think I can make a meaningful contribution to that victory, I am going to want to do my job. I hope that is how it turns out."

He added: "I think one of the really sad things about the British political and media maelstrom is the personal vilification individuals get from time to time. I don't think it helps any of us. I don't think it reflects well on any of us."

Mr Hester conceded that speaking out or dealing with political rows is "probably not my greatest specialty".

He added: "I think everyone has been caught a bit on the hop, including me."

Mr Hester noted that about £600 billion had been taken off RBS's balance sheet in its restructuring, "which is more than any Government has ever accomplished". He added: "We have to defuse this timebomb, and we have to do it in a public spotlight which is harsh."

Mr Hester, who has axed tens of thousands of jobs since succeeding Fred Goodwin in November 2008, highlighted a danger of further cuts if the economy failed to grow sufficiently. "If the economy isn't expanding and we are struggling to get the profitability our shareholders need, we have to continue to keep an eye on costs," he said. "Unfortunately, that means jobs."

Mr Hester steered clear of the independence debate and refused to discuss whether he had received alternative job offers, adding: "I want to win with RBS."

Earlier, he told the BBC he was "not a robot" and said there had been some "deeply depressing" moments over the bonus row.

He said: "In the end, in the intensity of it, I came to the conclusion that I thought it would be actually indulgent for me to resign and what I ought to do was to draw, if you like, on the reserves of strength I have and try to make RBS a success."

Meanwhile, Ed Miliband will today turn on George Osborne over the Chancellor's claims that Britain's bonus culture is crucial for a successful economy and that Labour made the UK appear anti-business.

Mr Miliband, in a speech to Sheffield University today, will say: "Mr Osborne wants to present himself as a champion of business, but the painful truth is he is the last bastion of an old mindset that is letting down British business and letting down British families."