Environment Agency chairman Sir Philip Dilley has quit after coming under fire for not returning from a family holiday in Barbados during the recent floods.
He said the decision to resign was because "expectations of the role have expanded to require the chairman to be available at short notice throughout the year", something he felt was "inappropriate".
He insisted he was "well qualified" to carry out the role but media scrutiny on him was "diverting attention" from efforts to help those affected by flooding.
In his resignation statement he said: "I want to be clear that I have not made any untrue or misleading statements, apart from approving the statement about my location over Christmas that in hindsight could have been clearer."
Responding to the resignation, Liberal Democrats Leader and Cumbrian MP Tim Farron said Mr Dilley should have joined his staff and been working over the Christmas break.