An actor dressed as a beefeater joins the strikers (Picture: PA).
Beefeaters working at the Tower of London are back on strike because of proposed changes to their pensions.
The beefeaters, and other GMB members working at Historic Royal Palaces, first went on strike in December.
Strikers are unhappy that their pensions have been changed from a final salary model to one described by the GMB as an "inferior" version.
The union say that last year Historical Royal Palaces recorded a profit of £3.1 million and that the government should step in to stop the pension changes.
Michael Ainsley, GMB Regional Organiser, said: "The government must not be allowed do a Pontius Pilate, washing its hands of this serious issue and standing by idly watching employers, particularly those they directly contract and who clearly can afford decent pensions, to kick the can down the road for tax payers to pick up the bill.
Further strikes are planned for 16 and 21 February.
John Barnes, Chief Executive of Historic Royal Palaces, said: "Our position has not changed.
"We remain committed to acting in the best interest of the charity, and the overwhelming majority of our staff, by closing the Defined Benefit Scheme.
"Only 11% of staff are in the scheme, yet it accounts for 50% of our pension costs.
"Having a small minority of staff benefiting so disproportionately is clearly unfair and unsustainable.
"Closing the scheme will enable us to increase employer contributions to pensions for everyone by 2% - an offer that is fundamentally fairer to our entire workforce."
Beefeaters, or Yeoman Warders as they are formally known, have guarded the Tower of London since Tudor times.
They wear a distinctive scarlet uniform and must have served at least 22 years in Her Majesty’s Armed Forces.