By Pawel Sobczak

WARSAW (Reuters) - Hundreds of Polish trade union members protesting against plans to raise the retirement age chained together barriers meant to keep them out of parliament on Friday, locking lawmakers in for more than an hour.

"We will decide when they will leave (parliament)," Solidarity trade union leader Piotr Duda said as the protesters surrounded the building, many waving flags emblazoned with the union's logo

"At least for once we will decide something instead of them."

The union members blocked lawmakers from leaving parliament after they voted to raise the retirement age as part of the government's drive to put the public finances on a more sustainable path. The protesters then unchained the barriers about one hour later.

The reform has sparked some of the biggest protests in recent years, led by Solidarity which is closely allied to the rightist opposition.

Under the reform, men and women will eventually retire at 67 - instead of 65 for men and 60 for women at present. Workers will be able to receive early partial pensions as part of a compromise reached within the governing coalition.

The bill, passed after a heated dispute between lawmakers, is expected to be cleared in the parliament's upper chamber and then signed into law by President Bronislaw Komorowski, a close ally of Prime Minister Donald Tusk.

STUMBLES

The pension reform controversy and several high-profile stumbles have sapped the popularity of Tusk's Civic Platform party which sank to record lows months after winning an unprecedented second consecutive term late last year.

Undeterred, Tusk on Friday also won the parliament's backing for curbing pension privileges for uniformed services that would prevent police officers and the military - among others - from retiring before they had completed 25 years of work and not before they had turned 55 years old.

The move, however, will only affect workers starting their service in 2013 and later. Currently uniformed services workers can retire after as little as 15 years.

Tusk says the reforms will prepare Poland for a demographic shift that is leaving fewer workers to collect funds for a growing number of retirees, but on Friday also called the vote "the most bitter victory" of his life.

His main political rival, Jaroslaw Kaczynski of the rightist Law and Justice party, vowed to ask the country's constitutional tribunal to reject the pension reform.

Solidarity leaders have warned they may renew their protests during the Euro 2012 soccer championship Poland is co-hosting with Ukraine next month - which Tusk hoped would boost the government's lagging support. Other labor groups have also threatened to hold protests.

(Writing by Chris Borowski and Gabriela Baczynska, Editing by Pravin Char)