NHS health unions have told the Westminster, Wales and Northern Ireland governments that a 3.3% pay increase is not enough to keep pace with the cost of living.
The RCN and 13 other NHS health unions have delivered a letter to health secretary James Murray.
Unions wrote to previous health secretary Wes Streeting back in March, calling for negotiations to improve both the 3.3% pay award and the AfC pay structure in England, Wales and Northern Ireland.
Talks have now begun and unions are calling for the health secretary to ensure that there is clear and significant investment in staff pay.
The letter is signed by 78,000 NHS staff.
The letter says: "3.3% is not enough and doesn’t address the longstanding unfairness of staff on AfC contracts getting less than other groups.
“NHS staff feel angry and let down. Day in, day out, it's a struggle to deal with understaffing, overwork and the constant feeling that – hard as staff try – patients are not getting the standard of care they should.
“Your 10-year plan aspires to make the NHS 'the country's best employer'. NHS staff now call on you to take the first step: recognise the problems with NHS pay and provide sufficient funding.”