Mr Scales, who currently earns £148,000, can look forward to earning a similar amount to former Translink chief executive Peter Strachan who pocketed £310,000 last year.

Mr Strachan is moving to the UK to oversee transport for next year’s Olympic Games in London.

Cllr Dowd said: “I have worked with Neil Scales for 15 years, and he has been a massive asset to Merseytravel and Merseyside.

“His expertise is not only known and appreciated here, but obviously overseas too, and this is a wonderful opportunity for him to further his career.

“He will be missed professionally, but it is also a great personal loss to me as both a friend and chairman, and to the organisation as a whole.”

Opposition Conservative leader Cllr Chris Blakeley said Mr Scales would be a real loss to Merseyside.

“He knows a huge amount about transport issues and is very well respected in the industry.

“I wonder why he started looking now, and the cynic in me would link the split over the U-turn over vertical integration.

“I hope Neil’s leaving will not be the start of a downward spiral.”

But Liberal Democrat leader Cllr Andrew Makinson said his group’s relationship with Mr Scales had “virtually broken down” in recent months.

It followed a high-profile falling out between Cllr Makinson and Merseytravel over authorised spending on the authority’s credit card by chairman Cllr Dowd.

Last night Cllr Makinson said: “I think Mr Scales has made the right decision and I wish him well in his future endeavours. Unfortunately the last few months have severely damaged the opposition's confidence in him as chief executive and relations have all but broken down.”

Next year’s vote on an elected mayor could see some transport powers transfered from Merseytravel but it is not known if this was a factor.