Another director announced her resignation from the board of the region's ambulance service this morning, becoming the second director to quit in two days.

Yesterday non-executive director Caroline Bailes resigned from the East of England Ambulance Service Trust (EEAST) following fierce criticism of the way the board has steered the trust through its current crisis and the lack of scrutiny it has given to officers.

And this morning a second non-executive director, Margaret Stockham, announced her resignation on social network site Twitter.

She wrote: 'Have stepped down from NED of EEAST.

'Sorry to leave but wish the board and their great staff all the best for the future.'

Mrs Stockham has been at the trust for less than a year, joining in July 2012.

The physiotherapist and consultant was supposed to remain in her post until June 2016.

Her resignation comes amid huge pressure being applied on non-executive directors by MPs.

Suffolk Costal MP Therese Coffey and Witham MP Priti Patel wrote to the five non-executive directors following a report which highlighted the failings on the trust's leadership and board.

The MPs' letters called on the five non-executive directors to resign immediately.