Leapfrog Day Nurseries, which offered childcare vouchers to HLS employees, is to sever all associations with the company after the directors of the nursery received letters that threatened its staff with physical force.
Leapfrog, which runs 102 nurseries and has become the biggest provider of childcare in the UK, has been the latest in a string of targets that have ties to HLS, which has been the subject of sustained protests over its use of animals, particularly in experiments in drug research.
The activists made their intentions clear on the website Bite Back, which stated that they had sent "warning letters" to firms supplying HLS, giving them seven days to end their relationship or "suffer the consequences."
A spokesman for the nursery firm told the Guardian newspaper: "Directors of Leapfrog Nurseries have received threats from animal liberation activists as a direct consequence of childcare vouchers being supplied to employees at HLS ..."
"Our business is childcare and we have to take every precaution when it comes to the security and safety of those children and our employees. Therefore the company has taken the decision to withdraw the scheme with immediate effect at HLS."
In related news, anti-vivisectionists claimed responsibility for leaving a device outside the home of Paul Blackburn, corporate controller of GlaxoSmithKline (GSK), earlier this month.
The Daily Telegraph reported that Blackburn had been abroad at the time but his wife and daughter were at the house. The device caused minor damage.
A posting on the website Bite Back said the ALF had carried out the attack because GSK was a customer of the animal testing group Huntingdon Life Sciences (HLS).
It warned the company: "We have identified and tracked down many of your senior executives and also junior staff, as well as those from other HLS customers."
"Drop HLS or you will face the consequences. For all the animals inside HLS, we will be back."