A united opposition today stalled proceedings in the Rajya Sabha pressing the government to come clear on the name of a union minister alleged to have links with a Bangladeshi arms dealer.

Opposition parties including the Left, BJP, AIADMK, Shiv Sena, SP, JD(U) and AGP persisted with their demand for a clearcut response from the government, stating it is a serious issue involving national security.

Raising the matter during Zero Hour, Moinul Hassan (CPI-M) said a central minister reportedly gave Rs 1.2 lakh to an arms dealer from Bangladesh through his partymen.

"This way, the minister and his colleagues are trying to destabilise the law and order situation in West Bengal," he alleged quoting a newspaper report, which said a central minister from the state gave money to buy illegal arms.

Unless the government discloses the name of the minister, the "needle of suspicion" would point at the entire council of ministers, who swear their allegiance to the Constitution, leader of opposition Arun Jaitley said.

The entire Opposition urged P J Kurien, who was in the Chair, to direct the government to respond. However, when Kurien said it was up to government to decide whether to respond, the members remained on their feet for about half an hour forcing adjournment of the House for 10 minutes.

When the House met again, pandemonium continued and the House had to be adjourned for 15 minutes ahead of the scheduled lunch break.

The response by the minister of state for parliamentary affairs Prithviraj Chavan that the government takes all issues raised during Zero Hour seriously triggered another bout of protest from the members.

"Government should come clear whether the news item was a story or a reality. If it is a reality, the name should be revealed, otherwise the guessing game will go on. Right from the Prime Minister, everybody comes under a question mark," S S Ahluwalia (BJP) said.

CPI-M leader Sitaram Yechury said his party would move a substantive motion naming the minister.

Alleging that his partymen are being killed in West Bengal, Hassan said the arms procured through Bangladesh route were used by Maoists and also in a robbery in Howrah.

He demanded that the contents of the conversation between the minister and the arms dealer be tapped and the government conduct a full inquiry.

Taking strong exception to Chavan's remarks that the government takes every issue raised during Zero Hour seriously, Brinda Karat (CPI-M) said a serious issue of national security is being "trivialised".

M Venkaiah Naidu (BJP) said government can say it will examine the issue and come back to the House tomorrow.

However, the government did not oblige him.

In the din, the Chair asked Mohammed Adeeb (Independent) to raise his mention regarding the Ajmer blast.

As he started speaking and alleged RSS hand in the incident, BJP members raised their pitch forcing the Chair to adjourn the House.