LONDON — Prime Minister David Cameron suffered a double setback on the eve of his Conservative Party’s annual conference as a second Tory lawmaker defected to the Independence Party and a junior minister resigned.

LONDON — Prime Minister David Cameron suffered a double setback on the eve of his Conservative Party’s annual conference as a second Tory lawmaker defected to the Independence Party and a junior minister resigned.

Mark Reckless, the Tory member of Parliament for Rochester and Strood in southeast England, announced his switch to UKIP in a surprise appearance at the fast-rising anti-European Union party’s own convention Saturday. Less than four hours later, Cameron’s office had to issue a statement announcing that Civil- Society Minister Brooks Newmark was quitting his job following allegations of sexual misconduct.

Twenty-four hours earlier, Cameron enjoyed a moment of triumph when an emergency session of Parliament approved his plan to deploy Royal Air Force jets to carry out airstrikes against Islamic State fighters in Iraq. Now, his party’s final big get-together before the May 7 general election has been ambushed by two embarrassments, with UKIP an ever-growing threat to the Tories’ chances of staying in power.

"It’s turned him from Winston Churchill to John Major — bulldog to beleaguered — in the course of an afternoon," Tim Bale, professor of politics at Queen Mary University in London, said in an interview. "Just because this was on the cards doesn’t make it any easier to cope with: It’s derailed a crucial conference and is the worst possible start to what will be a very long and grinding election year."

Reckless, who told cheering UKIP delegates Saturday that "the leadership of the Conservative Party is part of the problem that is holding our country back," said he’s resigning his seat in the House of Commons. He then plans to run as a UKIP candidate in a special election in his district. He’s following in the footsteps of Douglas Carswell, the first Tory to defect a month ago, who’s running for re-election for UKIP in his Clacton constituency to the east of London on Oct. 9.

Cameron condemned Reckless’s move Sunday, telling BBC Television’s "Andrew Marr Show" that "to act in a way that makes a Conservative government less likely is senseless and counterproductive." Carswell and Reckless are two people who "want to leave the European Union no matter what," he said in Birmingham, central England, the venue for the Tory conference. He called the news from the UKIP conference "frustrating."

After topping the ballot in the European Parliament elections in May, UKIP, which also campaigns for curbs on immigration, is now regularly polling about 15 percent support across the country. UKIP leader Nigel Farage told the conference Saturday he’s hoping his party may hold the balance of power in Parliament after the May 7 vote.

Cameron has attempted to head off the challenge from UKIP with a pledge to renegotiate Britain’s EU membership terms if he’s re-elected in May, and to hold a referendum by late 2017 on staying in the 28-member bloc. He told the BBC Sunday that immigration would be "at the heart" of his renegotiation demands.

For Bale, the difficulties facing Cameron are reminiscent of the travails endured by Major, the previous Conservative premier, who faced repeated criticism and scandals within the Tory ranks and eventually lost his majority in the House of Commons.

Reckless told UKIP delegates in Doncaster, northern England, that he believes the premier is only using the pledge of a referendum "as a device." He said voters had been "ripped off and lied to."

A ComRes poll for the Sunday Mirror and Independent on Sunday newspapers put UKIP support at 19 percent, in third place behind the Tories’ 29 percent and Labour’s 35 percent. Forty- three percent of UKIP backers voted Tory in 2010. ComRes interviewed 2,003 adults Sept. 24-26. It didn’t specify a margin of error.

Later Saturday, Cameron’s office announced the resignation of the Harvard-educated Newmark, whose responsibilities included charities and social investment. He said in an e-mailed statement that he’s leaving the government "having been notified of a story to be published in a Sunday newspaper" and asked for "the privacy of my family to be respected."

The Sunday Mirror reported on its website Sunday night that Newmark exchanged sexually explicit pictures with an undercover reporter posing as a female activist.

Cameron’s office named another Tory lawmaker, Rob Wilson, as Newmark’s replacement.

Reckless’s move presents Farage with the prospect of UKIP gaining its first two elected members of Parliament within a few weeks. Carswell is the clear favorite with bookmakers to be re- elected in Clacton.

The latest defector took 49.2 percent of the vote in his district in Kent in the 2010 general election, more than 20 percentage points ahead of the second-placed Labour Party candidate.

Still, "the seat is much less natural UKIP territory than Clacton, Rob Ford, co-author of "Revolt on the Right," a study of the party, said in an interview. "All hell will break loose if the Tories lose there. They gave up in Clacton, but they have to crush Reckless here."

Reckless told reporters he thinks he has "a fighting chance" of re-election, though Rochester is "not even in the top 100 of Conservative seats vulnerable to UKIP" in the 650- member House of Commons.

Michael Dugher, a senior lawmaker for Labour, called Reckless’s move "a hammer blow to David Cameron’s already weakened authority."

Farage told the BBC that "it wouldn’t surprise me if we saw more defections" and he’s also been holding talks with rank-and-file Labour lawmakers.

— With assistance from Jeremy Hodges in Doncaster, England.