Wiltshire Air Ambulance says it is still waiting to receive more than £100,000 in compensation after responding to the Novichok attacks in 2018.
The charity says it cost thousands to decontaminate their aircraft and support crews after flying to the aid of those involved.
This includes the attack on former Russian spy Sergei Skripal and his daughter Yulia in Salisbury in March 2018, and the fatal poisoning of Dawn Sturgess in Amesbury in June 2018.
David Philpott, who is chief executive of the service, said the airing of a new television series about the incident had “brought the matter into sharp focus”.
In February, all seven Wiltshire MPs, including the Lord Chancellor Robert Buckland, wrote to the Home Secretary in support of the claim, but to date the charity has heard nothing.