A CPI(M) member today demanded a roll back of the recent hike in excise duty on petroleum products and asked the government to pass on the "full benefit" of the sharp fall in global crude prices to the customers.

"It is a situation of 'heads I win, tails you lose'. Whenever there is a fall in international oil prices, the government does not transfer the full benefits to the people. Instead, it imposes further hikes in excise duties as it has done twice in the last one month," M B Rajesh said in Lok Sabha during Zero Hour.

He said the reduction in prices of petrol and diesel were much lower than the percentage decline in the global petroleum prices.

Rajesh was supported by members of the Left parties, Congress and other opposition parties.

Several members raised issues relating to farmers, with Supriya Sule (NCP) wanting urgent financial help to farmers of Maharashtra whose crop has been hit by heavy rains and hailstorm in the last few days.

Kirit Solanki (BJP) said cotton growers of Gujarat were on an agitation to demand minimum support price, while R Dhruvanarayana (Cong) wanted the government to raise customs duty on imported silk from 15 to 30% to help the domestic industry and silk producers.

Jayadev Galla (TDP) sought the setting up of chilli board on the lines of Tea and Coffee Boards to ramp up production, sale and export of Indian chilli, while Janardan Singh Sigriwal (BJP) wanted the Centre to help those farmers of Bihar who have been displaced due to floods and their cultivable land submerged.

Santokh Singh Chaudhary (Cong) asked the government to withdraw the 12.36% service tax on remittances by Indians settled abroad, saying this would encourage black money and hawala.

Raising the issue of ban on stem cell research, Dinesh Trivedi (Trinamool Congress) urged the government to allow basic research on embryonic stem cells, saying the ban has resulted in a lot of hard work and funds going down the drain.

"Given the knowhow, and the expertise of our scientific minds, India is one of the very few countries which can become a pioneer in this field," he said.