WASHINGTON — If any Republican lawmakers are worried about “the environmental lobby and their extremist friends in the eco-terrorist underworld,” the House GOP leadership has some advice for them:

Plant some trees. Adopt a highway. Tour a recycling plant. Clean up a park. Above all, invite the press. Such moves will draw positive media coverage and “help further insulate yourself from the attacks of the green extremists,” the House Republican Conference says in an internal memo to the troops.

The document acknowledges that “the environment is an important issue” to “many in our growing Republican majority.” But it says that the party’s “common sense reforms” to such laws as the Endangered Species Act, Superfund and the Clean Water Act could leave its members vulnerable to criticism.

Not to worry: Republicans can “go over the heads of the elitist environmental movement” by being visible at home.

“In order to build credibility,” the memo says, “you must engage this agenda before your opponents can label your efforts `craven, election-year gimmicks. … Your constituents will give you more credit for showing up on a Saturday to help clean up the local park or beach than they will give a press release from some Washington-based special interest group.”

Other pointers: “Consider passing out tree saplings with your door to door pamphlet. … Start a conservation task force.”