SILIGURI, Jan. 16 -- Opposition parties in Sikkim are set to forge an alliance in a bid to challenge the ruling Sikkim Democratic Front (SDF) led by Pawan Chamling that has been ruling the tiny Himalayan state since 1994. As a first step, Sikkim Krantikari Morcha (SKM) president P S Golay and Hamro Sikkim Party (HSP) Bhaichung Bhutia on Tuesday held a closed-door meeting on Tuesday. If the tie-up eventually materialises, it will be the first time an alliance of opposition parties will be forged in the 44-year history of Sikkim. The state is due to hold assembly polls this year. "The meeting was positive...We will again meet on January 31 along with the executive committee members of both parties," said Golay....