National Gallery security cutbacks are putting paintings in danger from protesters, curators have privately warned.
Staff were shocked to see protesters using hammers to smash the glass on Velazquez’s Rokeby Venus earlier this month while paintings by Constable and Van Gogh were targeted last year.
Curators fear that a reduction in security guards has made the collection more vulnerable to damage or theft.
In the past, every room was patrolled but now guards are each assigned to protect as many as three or four rooms, curators said.
One warned that the room housing King Charles’s current loan of Mantegna’s monumental paintings, The Triumphs of Caesar, was “empty for large sections of the day”.
“Guards are having to do three rooms,” they said. “You can’t be in three places at once and there are large sections of the day where there’s no security in there at all.
“If King Charles’s loans got damaged, that would ruin any hope of further loans. Yet, the internal reports that we’re getting on the security is that everything went fine.”
Referencing the Just Stop Oil protest, they added: “If you’re letting hammers into the National Gallery, you’ve got a serious problem with security.
“All museums and galleries, even in Europe, have problems with Just Stop Oil, but this is becoming a sort of epidemic now.
“The morale around the place is pretty low because there’s nothing to indicate that anything is going to change.”
Curators say that the Rokeby Venus targeted last month has been damaged because of smashed glass which can scratch the surface or get embedded in the canvas.
A National Gallery spokesman said that “minimal damage” has been sustained to the surface of the painting.
But, while he confirmed that it is “not back on display yet”, a curator said: “Normally the Gallery likes to put things straight back on, to show people there’s nothing to worry about.”
Last year, Just Stop Oil protesters stuck an “apocalyptic” version of Constable’s The Hay Wain over the painting and glued their hands to the frame.
In a further incident, they hurled tomato soup at Van Gogh’s Sunflowers, before glueing themselves to a wall. They were able to give speeches before being apprehended.
The National Gallery later said that experts found minor damage to the frame and the varnish covering the Constable. As the Van Gogh painting was covered by a sheet of glass, it was unharmed, the gallery said. The frame sustained some minor damage.
Michael Daley, director of ArtWatch UK, the museums and galleries watchdog, said of the Rokeby Venus attack: “They have escalated from affixing themselves or messages to the glass protection to smashing the reinforced glass itself with security hammers of the kind found on trains. The violence has now become real rather than symbolic.”
He added: “Museums are understandably loath to discuss security procedures, but it’s now clear that the switch from old-style warding staff – who were often ex-military or police men – to fewer and friendlier greeter-style staff has increased the likelihood of assaults on famous works of art.
“Where once attacks came primarily from disturbed individuals, today they are a soft touch option for political activists who seem to appreciate that staff are instructed not to intervene but simply to report incidents.
“This soft and indulgent – if not complicit – policy leaves activists free to carry out increasingly destructive assaults and then to spew out and broadcast agit-prop.”
‘Properly staffed security teams needed’
Mark Serwotka, general secretary of the PCS union, which represents several members of National Gallery staff, said: “The safety of our national collection is one of the most important functions of our museums and galleries.
“Though PCS has long campaigned for fully staffed, in-house security teams, management in these national institutions have stripped back investment in security and outsourced many key staff – all to reduce headcount and cut costs.
“The most recent incident at the National Gallery is yet another demonstration why properly staffed security teams are needed to safeguard vital collections in what are some of our greatest cultural institutions.”
The National Gallery spokesman said: “Security is of the highest priority and any changes to its arrangements are approved by the national security adviser for museums.”