Engaging India is an online column analysing the issues, trends and forces behind the business and politics shaping India and its impact on the world. Engaging India appears exclusively on FT.com India, a dedicated online section on India, and contributors include the Financial Times' Amy Kazmin, New Delhi correspondent; and Joe Leahy, Mumbai correspondent.

Mayors of cities I have lived in lately are either busy "cleaning" things up - or in some instances, making a mess of them.

Job Choen, mayor of Amsterdam - where I was studying before I returned recently to Mumbai, was "cleaning up" a global tourist destination of its "sinful ways" by coming down heavily on drug cafes and brothels.

And now in Mumbai I find that the mayor of India's run-down financial capital, a city that needs plenty of cleaning up in the most literal sense, is dabbling in language politics instead.

I did not learn Dutch in Amsterdam, just as I never felt the need in Mumbai to study Marathi - the regional language of the state of Maharastra, of which Mumbai is the capital. English and even a little Hindi was all you needed to get you around in this multicultural metropolis, whose 12m inhabitants come from all over India and are mostly just interested in making a buck.

But that is not the case any longer, as I found out when I caught up with a friend, a non-Marathi speaking journalist who covers local government affairs at the city council.

Until about a month ago, most official documents of the Brihanmumbai Municipal Corporation (BMC), the city council's Marathi name, were available in at least two languages - Hindi and Marathi, as well as sometimes in English. But thanks to the city's new Mayor Shubha Raul, a member of the rightwing Hindu regionalist Shiv Sena party, the BMC has now gone "100 per cent Marathi".

Application forms filled in using English or Hindi are not accepted once you pass under the gothic entranceway of the BMC's magnificent colonial era office, which is near the city's landmark railway station Victoria Terminus. (VT is today known by its Marathi name, Chhatrapati Shivaji, a 16th century Hindu warrior king famed in Maharashtra for fighting India's Muslim Mughal invaders.)

Even the software in the council's computer systems is being converted to Marathi from English and any new data must be entered in the local language.

My journalist friend said that like many other people who must deal regularly with the council, this has made his life a nightmare. "By the time I am done translating these press releases, it's almost past the deadline," he complained.

Mumbai, less than 40 per cent of whose populations are fluent in the state's local language, uses the colonial language as the lingua franca to conduct its business. Even most BMC-run schools use English as their medium of instruction.

The move to Marathi is part of rising regionalism in many states, with the government in Bangalore, India's equivalent of Silicon Valley, recently changing the city's name to Bengaluru. The move by Ms Raul's party to change the city's administrative language to Marathi comes ahead of a state election in Maharashtra next year.

The language change is also causing problems for many city councillors, who normally use English and Hindi to debate about the city's complex problems, such as how to clear the slums that house more than half its population or how to improve its creaking infrastructure.

"I have lived in Mumbai for 45 years but being able to speak a language is quite different from being able to read it," says Adolf D'souza, who represents the western suburbs, known as the Beverly Hills of Mumbai owing to the many Bollywood celebrities who live there.

The voluminous agenda of the house is now available only in Marathi. "How are we supposed to debate an issue in the house when even the agenda is incomprehensible?" says Mr. D' Souza, expressing the agony of at least 40 out of the 227 counselors in the chamber of the city council who struggle with the language.

The local and the global often impact one another and Mumbai is witnessing just that. Mumbai's business elite, which wants the city to become an international financial centre (IFC), opposes the language change.

"It will have an adverse effect on the global investment climate in the city," warns Sushil Jiwarajka, the western regional council chairman of the Federation of Indian chambers of commerce and Industry.

Former World Bank economist Percy Mistry, who advised India's finance ministry on how to help Mumbai realize its dream of catching up with London and Hong Kong, said that an unfriendly business climate would just give companies another reason to choose cities in neighboring Indian states, such as Gujarat, rather than Maharashtra.

The source of the problem is a wave of parochialism started by Hindu nationalist parties, such as the Shiv Sena, which have a clear majority of the seats in the BMC chamber. It was the Shiv Sena that first changed the name of the city from Bombay to the local word, Mumbai, in 1995.

Spurred on by the Shiv Sena, the BMC has ordered restaurants and stores to use Marathi and English on their name boards while cinemas are being urged to screen Marathi language films. Restaurants have voluntarily changed their names for fear of being targetted by workers of right-wing parties. One restaurant, "Bombay Blue", changed its name to 'Mumbai Blue'.

The Congress party alliance that runs the state government does not want to miss out on the Hindu regionalist vote either. It has proposed building a statue of Shivaji that will be taller than New York's Lady Liberty, in the Arabian Sea on the city's west coast. The government has invited tenders from firms across the globe.

The vast amounts of time and money required for jingoistic exercises like the change of administrative language and the construction of the statue exasperate many citizens. Mumbai is the richest city council in the country - it's latest annual budget was Rs160bn. It employs more people than most of India's big companies. Yet the city government has done little to solve problems such as the spread of slums, flooding during the annual monsoon and the condition of Mumbai's potholed roads.

But Sameer Desai, an English speaking BMC councillor from the Congress party, has learned from long experience that in Mumbai, it is difficult to go against the tide. While Congress opposes the language measure, in the meantime, his solution is simply to clean up his Marathi. "I have started reading more administrative documents than before to brush up my language skills," he says.

That may be fine for city councillors, who have a lot of time on their hands, but what about rest of us?