BBC analysis of data from the Ministry of Housing, Communities and Local Government found councils across England reported 73% more unauthorised traveller caravans in January 2026 compared to January 2020.
The numbers rose from 2,860 to 4,950.
The summer count of caravans, carried out each July, saw a 44% rise between 2019 and 2025, from 3,113 to 4,471.
The Conservatives said leaving the European Convention on Human Rights (ECHR) – a policy the party first announced in October – would allow them to tighten planning laws and reduce the number of caravans installed without permission.
Cleverly, whose Braintree constituency saw a caravan site built over a weekend in May allegedly without permission, accused Labour ministers of “turning a blind eye” to the issue.
He added: “A small minority of travellers are breaking the rules, and all too often, it is going unpunished.
“This cannot be allowed to continue.”
