Describing the influx of Rohingya refugees into India as "very serious", the Congress on Friday demanded that the central government involve all parties to formulate a policy on the matter."This is a very serious matter. In the interest of the nation, all political parties should come together to take a decision on this."The government should invite representatives of all parties and lay down a policy. Since the country's interests as well as decisions with long-term effects are involved, we want the policy be formulated by all the parties," Congress Spokesperson Ajay Maken said here."It should not be a policy of one party," he added.Union Home Minister Rajnath Singh on Friday said the government will inform the Supreme Court of its stand on the Rohingyas in India on September 18.On Monday, the apex court will hear a plea that challenged the Centre's decision to deport illegal immigrants among the Rohingya Muslims to Myanmar.