The fresh outburst by Maharashtra Navnirman Sena chief Raj Thackeray against north Indian migrants has brought back a political headache the state Government thought it had got rid of.

A day after Raj launched a new broadside against migrants, the Congress-NCP alliance was in a dilemma over whether it should prosecute him or ignore it as rhetoric, as it did for a while three months ago until the pressure got too much.

Although there has been no violence in Mumbai or Maharashtra after Raj's fresh verbal assault during the second anniversary celebrations of his party, most politicians from across the spectrum on Sunday demanded that the Vilasrao Deshmukh Government act against him.

Addressing tens of thousands of supporters in Mumbai on Saturday, Raj said that he would not hesitate to drive migrants from north India out of Mumbai if the need arose, blamed migrants from Uttar Pradesh for soaring crimes and urged locals to take on migrants if necessary.

Considering he had been arrested briefly, gagged and allowed to hold his rally after being warned that he should not provoke people, Raj was "challenging the whole system", said Congress spokesman Sanjay Nirupam, and sought action.

Responding to questions on the matter in Bangalore, BJP president Rajnath Singh criticised Raj, saying "people who indulge in politics of casteism and regionalism should have no place in the country's polity".

Shyamsunder Arya, chief general secretary of the Samajwadi Party in Mumbai, ridiculed Raj as "a non-serious politician" and alleged that the state Government was letting him off.

Sources in the Government, however, said the alliance had its own calculations to keep in mind before considering action against Raj. One source said that the MNS chief's brand of politics may eventually cut into the Shiv Sena's vote base, particularly in the Mumbai, Nashik, Thane and Pune belt and the Konkan region.

As a result, there was no official word from the Government about Raj's speech, and all that Mumbai police said was that it was studying the transcript and consulting legal experts before considering action. That there are divergent views within the Congress-NCP alliance was apparent when NCP MLC and general secretary Gurunath Kulkarni said "the wrong stance taken by the state Government had led to crowds turning up at the Shivaji Park rally".

"The action against MNS activists led to general curiosity in the minds of the youth, which helped the turnout," he added. "There is freedom of speech. The points in his speech can be replied to."

Raj's fresh outburst has also apparently ruffled the Shiv Sena which, like the last time around, sought to play up its own record in championing the cause of Maharashtrians. "The bond between Maharashtrians and the Shiv Sena is unbreakable," party chief Bal Thackeray said in a recorded message at a career fair organised by his party on Sunday. "There are some people who are creating a ruckus in the name of Marathi. But if you look at the history of the Sena, when some communities came to Maharashtra and took over our jobs, then the Shiv Sena stood firmly behind Maharashtrians. If not, Maharashtrians would not have been visible (in Mumbai)."

Raj's estranged cousin Uddhav said at the fair that Maharashtrians in the villages and districts should come to Mumbai to seek their fortunes and better their lot as "they had a right over Mumbai". While migrants were welcome, they had no right to target the roots of the locals, he said