The police and crime commissioner for Wiltshire and Swindon has expressed concern about how the nerve agent poisonings in Salisbury and Amesbury are stretching the resources of forces across the country.

Rest days have been cancelled and annual leave requests put on hold for Wiltshire officers and colleagues from many other forces who have been drafted in to help deal with the aftermath of the latest novichok incidents.

Angus Macpherson said other major events such as Donald Trump’s visit to the UK and this weekend’s airshow in Fairford, Gloucestershire, were adding to the problem.

Macpherson said: “Across the country police forces are currently facing an extraordinary level of demand on their resources – due to the mutual aid support required for the presidential visit, Royal International Air Tattoo, large summer events and the ongoing major incidents in Amesbury and Salisbury amongst others – alongside the delivery of day-to-day policing.”

He said he had raised the issue with the policing minister, Nick Hurd. “He has reassured me that the current approach to policing cordons, in relation to the ongoing major incidents in Amesbury and Salisbury, is under review to help me ensure that policing services more widely across Wiltshire and Swindon remain unaffected.”

Scores of officers are guarding sites at the centre of the latest poisoning, including the home of Dawn Sturgess, who died after being exposed to novichok, and that of her partner, Charlie Rowley, who remains in hospital. Another large cordon is in place around the Queen Elizabeth Gardens park in Salisbury.

“Wiltshire police has received great support from almost every police force across the country since the first major incident was declared in March,” said Macpherson.

“Alongside the chief constable I couldn’t be more grateful for the help and support of those forces. However, with more and more rest days being cancelled and annual leave requests being put on hold, we must now explore a different approach.

“I continue to be amazed by the one team mentality of all those supporting us during this incident and it is testament to the selfless and dedicated officers, staff and volunteers that work together to keep our country safe.”

Sergei Skripal and his daughter, Yulia, were poisoned with novichok in Salisbury in March. Sturgess, 44, and Rowley, 45, collapsed at the latter’s home in Amesbury on 30 June, having been exposed to the nerve agent.

The government has pledged £4.1m towards the costs incurred by Wiltshire police after the poisoning of the Skripals.

Two more vehicles have been seized by police as part of the investigation into the latest poisonings. One is understood to be a police car that had been parked in Chippenham, 36 miles north of Salisbury. The other is a rapid response vehicle taken from the air ambulance base in Semington, 30 miles north of the city.

Both are believed to have been involved in the initial response to the poisoning of Sturgess and Rowley.

Wiltshire police also said a man had been cautioned for being drunk and disorderly after an incident in Salisbury on Thursday that led to a street being cordoned off. The man was taken to Salisbury district hospital to check whether he had been exposed to novichok but tests were negative.

A police spokesperson said: “We understand that our initial response to the incident may have looked alarming, but we hope you appreciate why we needed to take this highly precautionary measure.”

A Home Office spokesperson said: “The government stands in full support of the local community in Salisbury and Amesbury and remains committed to working alongside the local authority and emergency services to help the area meet any further exceptional costs arising from this incident.”