WASHINGTON — Republicans are ready to muscle legislation through the House authorizing an election-year lawsuit against President Barack Obama that accuses him of exceeding his powers in enforcing his health care law.

A party-line vote — and plenty of sharp partisan rhetoric — was expected when the GOP-led chamber considers the measure Wednesday.

Democrats dismiss the proposal as a legally groundless exercise that could end up costing taxpayers millions of dollars in legal fees and other expenses.

They’ve branded the effort a political charade aimed at stirring up Republican voters for the fall congressional elections. They say it’s also an effort by top Republicans to mollify conservatives who want Obama to be impeached — something House Speaker John Boehner, R-Ohio, said Tuesday he has no plans to do.

“This lawsuit is frivolous on steroids,” Rep. Alcee Hastings, D-Fla., said Tuesday as the House Rules Committee met to clear the way for Wednesday’s debate. “It’s absolutely insane what you all are doing.”

That hasn’t stopped Democrats from sending fundraising pleas to their own supporters warning that the GOP is out to impeach Obama and ruin his presidency. Using that pitch, Democrats raised $1 million Monday, according to the head of the House Democratic campaign organization, Rep. Steve Israel, D-N.Y.

Republicans say the House’s planned legal action is warranted because Obama has violated his constitutional duty to faithfully execute the laws. They say that instead, he has enforced laws as he wants to, dangerously shifting power to the presidency from Congress.

“It is to preserve this country, the separation of powers and the rule of law,” said Rep. Virginia Foxx, R-N.C.

The lawsuit will focus on how Obama has carried out his health care overhaul, a 2010 law that is one of his most prized domestic achievements and that every GOP lawmaker opposed.

Republicans say Obama has illegally changed the law using executive actions. The White House and Democrats say he’s acted legally and within the latitude he’s empowered to use as chief executive.

In particular, Republicans have objected that Obama has twice delayed the law’s so-called employer mandate, which he did under pressure from business groups. The provision requires companies with 50 or more employees working at least 30 hours weekly to offer health care coverage or pay fines, while businesses with fewer than 50 workers are exempt.

The requirement was initially to take effect this year. Now, companies with 50 to 99 employees have until 2016 to comply, while bigger companies have until next year.

Republicans say there are other examples of Obama exceeding his powers. These include failing to notify Congress in advance when he traded five Taliban members held at the prison at Guantanamo Bay, Cuba, for the captive Army Sergeant Bowe Bergdahl, and unilaterally preventing the deportation of some children who illegally immigrated to the U.S.

They also point to Obama’s comments in January that 2014 would be a “year of action” to implement his priorities, which he said he would do “with or without Congress” by using his “pen and the phone.”

“Such a shift in power should alarm members of both political parties because it threatens the very institution of the Congress,” said a GOP-written report accompanying the legislation.