Blood donors are being urged to keep appointments over Easter and into April and May to help meet a shortage of supplies in London.

Blood stocks are more likely to drop around Easter and May Bank Holidays when people are away, the NHS points out.

There is a shortage of O-Negative blood type for patients needing emergency transfusions, although all blood types are needed.

“It is vital that we collect enough to meet hospital demand,” NHS Blood Donor director Mark Chambers said. “We need donors this Easter, especially O-Neg blood group.”

Stocks are also needed for cancer patients and those with blood disorders or undergoing surgery.

There are more than 4,000 spare slots over the next fortnight at donor centres across London.

These include Stratford (Westfield shopping centre) with 1,500 available, Shepherd’s Bush (also Westfield) with 900, Tooting (Cranmer Terrace) 570 and West End (Margaret Street, off Regent Street) 1,300.

Appointments can be by phone on 030-0123 2323 or the “” website.