NHS campaigner Julie Bailey, who set up Cure the NHS after her mother Bella died at Stafford Hospital in 2007, has said she will ask members of the NHS Commissioning Board to call for their boss' resignation:
We want his [Sir David Nicholson's] resignation, if not his sacking.
He has brought the NHS into disrepute.
We are planning to lobby members of the board to call for him to resign.
More top news
The singer had been tweeting in support of migrants when she was bombarded with abusive messages.
Ministers are reportedly considering plans in a bid to lower inward migration.
In a tweet on Saturday, the US president didn't give a reason for his absence but said he wished"everyone well and have a great evening".