Waterford — Heather Somers, the Republican candidate for lieutenant governor, joined state and local officials today in denouncing Gov. Dannel P. Malloy’s decision to turn the former Seaside Regional Center property into a state park.

Somers, a former Groton town mayor, called Malloy’s change in course a heavy-handed “political gambit” that will cost the town of Waterford jobs and tax revenue. She also faulted the governor for offering no plan for maintaining the Shore Road site’s historic buildings.

“Connecticut needs a new administration and new leaders who are committed to working with local leaders to promote job growth and reduce taxes,” Somers said, standing on the state-owned property that’s been vacant since the 1990s.

Republicans Dan Steward, the Waterford first selectman; Paul Formica, the East Lyme first selectman and state Senate candidate; and Len Fasano of North Haven, the state Senate minority leader pro tempore, also spoke.

Steward said the town has been working to promote private development of the Seaside property for 15 years and noted that the preferred developer, Mark Steiner, has a plan to develop a 40-room inn, a banquet facility and 80 high-end housing units on the site. Malloy’s move to terminate Steiner’s contract with the state will lead to costly litigation for both sides, Steward said.

The state stands to lose the $8 million purchase price Steiner had agreed to pay for the property and will have to incur the cost of cleaning up the contaminated site — $30 million to $40 million, the first selectman said.