New Delhi, Nov 8 (IANS): The BJP members Thursday ended their boycott of a parliamentary panel probing the 2G spectrum allocation issue and reiterated their demand for calling Prime Minister Manmohan Singh and Finance Minister P. Chidambaram as witnesses.

According to parliamentary sources, Bharatiya Janata Party member Yashwant Sinha said that calling the prime minister and Chidambaram had become "more urgent" after the statement of former cabinet secretary K.M. Chandrasekhar before the joint parliamentary committee (JPC) looking into the issue.

Chandrasekhar had earlier told the JPC that he had written to the prime minister suggesting an increase in the licence fee for 2G spectrum to enable the government earn an additional Rs.35,000 crore revenue.

The BJP had quit the panel over its demand around two months ago.

According to sources, a Congress member, in turn, demanded that BJP leader and former prime minister Atal Bihari Vajpayee should also be called by the JPC.

The JPC meeting was called to record the views of the Cellular Operators Association of India.