WASHINGTON: A rift within the Republican Party is widening in the aftermath of its clear defeat in the budget-debt brawl that threatened a default and shutdown much of the US federal government for 16 days.

Implored by House Speaker John Boehner to unite and “fight another day” against President Barack Obama and Democrats, Republicans are instead intensifying attacks on one another.

That’s an ominous sign for the party in advance of 2014 midterm elections and more difficult policy fights soon to arise in Washington.

Many Republican veterans are seething over what they say was an exercise in self-destruction: A strategy, pushed by the hardcore conservative tea party movement, to use legislation needed to keep the government running and prevent a debt default as leverage to derail Obama’s signature health care reform.

In the end, the Republicans got none of their demands and polls showed most Americans blamed the party for the shutdown.

The crisis has complicated the debate the Republican Party has been having about its future since failing to recapture the White House and the Senate in last year’s elections. Some senior Republicans say the shutdown fiasco demonstrated that tea party tactics, while energising the conservative base, are alienating moderate voters the party needs to remain competitive in national elections.

Far from showing remorse, the tea party faction is vowing to keep up the effort to repeal the health care law, widely known as “Obamacare.’’

Moreover, tea party groups are stepping up efforts to use primary elections next year to oust some of the more pragmatic Republican lawmakers who voted in favour of the bipartisan deal that ended the shutdown, furious that they caved into the Democrats. Since the end of the shutdown, the Twitterverse has crackled with threats, insults and the names of the 27 Republican senators and 87 Republican House members who voted for the agreement that reopened the government and raised the nation’s borrowing limit. Within hours, TeaParty.net tweeted a link to the 114 lawmakers, tagging each as a Republican in name only who should be turned out of office: “Your 2014 (hash) RINO hunting list!” RINO stands for “Republican In Name Only.’’

The tea party movement gained strength after the passage three years ago of Obama’s health care overhaul, which is intended to extend affordable coverage to millions of Americans currently lacking insurance. The tea party considers the program the embodiment of the big-government overreach they oppose, especially a requirement in the law that Americans have health insurance or face fines.

The emergence of the tea party re-energised the Republican Party and helped it recapture the House in 2010 with the rise of a new crop of hard-charging young lawmakers. It remains a formidable force despite a loss of momentum last year when Obama easily won re-election and the Democrats held on to the Senate. Many of tea party-backed lawmakers represent extremely conservative congressional districts that have emerged over the years as lawmakers from both parties have redrawn the electoral map.

As a result, many Republican lawmakers are more concerned with surviving potential primary challenges from tea party candidates than losing the general elections to Democratic rivals.

Senate Minority Leader Mitch McConnell, the Kentucky Republican who helped broker the bipartisan deal to end the shutdown, is facing one such challenge.

The Senate Conservative Fund, which raised nearly $2 million for tea party candidates in last year’s elections, announced Thursday it was endorsing McConnell’s Republican primary opponent, Matt Bevin. Another group, Tea Party Victory Fund Inc., wrote in a fundraising letter, “We shouldn’t have to put up with fake conservatives like Mitch McConnell.’’ There were more tea party targets: Republican Sens. Lindsey Graham in South Carolina and Lamar Alexander in Tennessee also are seeking re-election.

Such a strategy has risks for the Republican Party. Some tea party candidates who won surprise primary victories last year went on to capture their congressional seats, including Sen. Ted Cruz of Texas, who championed the shutdown strategy. But others won the primaries only to be defeated by Democratic candidates who had appeared on course to lose to more mainstream Republican candidates.

The divide has defined the warring Republican factions ahead of next year’s midterm elections, when 35 seats in the Democratic-controlled Senate and all 435 seats in the Republican-dominated House will be on the ballot. In the nearer term, difficult debates over immigration and farm policy loom, along with another round of budget and debt talks.

A Pew Research Centre poll released this week showed public favourability for the Tea Party dropped to its lowest level since driving the Republican takeover of the House in the 2010 elections. An AP-Gfk poll showed that 70 percent now hold unfavourable views of the Tea Party. And yet, House Republican leaders tried again and again to resolve the standoff the tea party’s way _ by demanding limits on Obamacare in exchange for reopening the government _ until they ran of options and accepted the bipartisan deal.

Despite the tea party backlash against him, McConnell vowed he would not permit another government shutdown. ’’I think we have now fully acquainted our new members with what a losing strategy that is,” McConnell said in an interview with The Hill newspaper.—AP