Tell them that you want to oppose planning permission on the grounds that the lab will hold deadly viruses that pose a virus leak hazard threat to all, wherever you mgiht live. You can also state that action and protests from Animal Rights activists and local campigners will cause disruption both locally and at council services.
The lab will be alongside St Pancras International posing a major catastrophe threat.
The building of the lab will cause disruption, noise, dust etc. The area needs homes and community facilities.
There are fears that the lab will be patrolled by armed police particularly since the nearby offices of the Guardian newspaper had their windows shot out by a sniper.
Conatminated viral tissue will be transported through one of the most congested areas in London.
Unfortunately you cannot use animal cruelty as a reason for opposing planning permission.