The Government has announced that almost 1.4 million public sector employees will receive a 1% pay rise from next month.
The Treasury said recommendations from a number of pay review bodies had been accepted, sparking anger from unions.
Unison, which represents 450,000 NHS workers including nurses, paramedics, therapists and midwives, said staff face another year of financial hardship.
The union condemned the second successive 1% annual increase as a "squeeze" on pay, which officials warned would leave many health workers and their families struggling to make ends meet.
More top news
The threat level has been raised to critical by MI5's Counter-Terrorism Analysis Centre.
Prime Minister Theresa May announced the decision from Downing Street.
A man, apparently armed with a small axe and a large stick, was detained close to the event and police cleared the area as a precaution.