Mr Johnson is well-known for his outspoken and controversial views on Brexit.
This follows the introduction of safe staffing legislation in Wales and Scotland.
The college was unable to disclose the content or outcome of the meeting.
It would cost a massive £6 billion to undertake all the required repairs.
The letter calls on the leadership hopefuls to clarify their positions on safe staffing, pay and tuition fees.
It is the first legislation of this kind in the UK to apply to both health and social care services.
There are currently over 40,000 vacant registered nursing posts in England.
Contracts will not need to be changed and staff will not have to re-apply for their current positions.
Staff should offer support "to get away from knife crime".
The Chief People Officer will ensure the NHS has enough people, with the right skills and experience to deliver the NHS Long Term Plan.
The basic salary paid to MPs will have risen by £13,730 since April 2010
The UK is still on course to leave the EU on March the 29th but the defeat throws doubt over the terms of the withdrawal.
The RCN is calling on the Government to waive the Immigration Health Surcharge for non-EEA nursing staff.
The Royal College of Nursing has warned that chronic staffing shortages could undermine the goals set out in the NHS Long Term plan.
"In the UK, we are spending £97bn of public money on treating disease and only £8bn preventing it across the UK".