* Tourism minister is fifth to quit cabinet this year

* Action reminder of Rousseff government's vulnerability

* Unlikely to affect preparations for 2014 World Cup

 BRASILIA - Brazil's tourism minister resigned on Wednesday over allegations of ethics violations, a departure that President Dilma Rousseff hopes will signal the end of months of scandals and negative headlines.

The resignation of Pedro Novais -- the fifth cabinet member to resign in just over three months -- is a reminder of the political volatility that has undermined Rousseff's administration as she struggles to contain unrest within her ruling coalition stemming partly from fiscal belt-tightening.

But Novais' departure is likely to bring some relief to Rousseff as she tries to distance herself from the corrupt, sleazy style of politics that has been portrayed by a series of media reports on the Tourism Ministry under Novais' command.

A steady stream of scandal allegations has eased in recent weeks as Rousseff has moved to patch up relations with her biggest coalition partner, the PMDB, of which Novais is a member.

In August, police arrested 33 Tourism Ministry officials and entrepreneurs in a corruption sweep tied to funding for major sports events.

Novais also made headlines for allegedly having claimed payments made at a sex motel as official expenses.

In the latest allegation against him, Novais was accused in newspaper reports this week of having used public funds to employ a maid and a chauffeur for his wife while he was congressman from 2003 to 2010.

Budget cuts ordered by Rousseff earlier this year to stem inflation have starved lawmakers of funds and aggravated a series of ethics scandals that resulted in the resignation of the five ministers in just over three months.

Upset with Rousseff's tough stance on the budget and corruption, several allies openly boycotted her legislative agenda for several days in July. They demanded an increase in discretionary funds for legislators and more appointments to lucrative government jobs for their parties.

But the latest resignation could boost Rousseff's control over the often rebellious PMDB, which risks losing support among middle-class voters who are growing tired of corruption allegations. Three of the five disgraced ministers belonged to the PMDB.

Unlike her predecessor, Luiz Inacio Lula da Silva, who often turned a blind eye to corruption allegations for the sake of maintaining political support, Rousseff has shown less tolerance for nepotism and wrongdoing.

She has sought to appoint more technocrats like herself rather than politicians to second-tier positions in government, another sore point for her coalition allies.

All five of the ministers who stepped down since June were either nominated by Lula or recommended by Rousseff's allies as part of a power-sharing agreement.

Novais' departure is unlikely to significantly change Brazil's preparations for the 2014 soccer World Cup or the Olympics to be hosted in Rio de Janeiro two years later.