Newby Hall owner Compton said HHA properties support 26,000 jobs and 52,000 businesses. Politicians "appear to have so little time to understand the link between heritage and tourism", he added. They spend £102m annually on repairs, down from £137m in 2009. The repair backlog is £764m.
The HHA will issue a policy statement in 2014 before the next general election. This will show the association's role in promoting tourism. In 2016, the HHA will celebrate the 300th anniversary of the birth of Capability Brown. Half of his landscapes are owned by members.
A new HHA video includes Levens head gardener Chris Crowder and Doddington Hall owner Claire Birch talking about gardens and how they attract visitors.
Professional Gardeners Guild chairman Tony Arnold said other industry bodies are supporting a future campaign around the guild's recent salary survey.