Unable to bear the ‘agony’ caused by continued non-payment of their pay dues, eight Air India unions on Wednesday sought immediate intervention of the Prime Minister to resolve the situation, failing which they threatened to proceed on strike from April 2. The decision to go ahead with their proposed strike came after the unions failed to secure any ‘firm proposal’ from the debt-ridden government carrier for clearing their dues at a meeting with the management in Mumbai on Wednesday, the third such engagement in a week.