New Delhi, May 21: All eyes are on Mayavati as she prepares to arrive in Delhi on Friday bearing the promise of letting on who she wants next in Rashtrapati Bhavan.

The Uttar Pradesh chief minister, whose Bahujan Samaj Party votes are crucial to the presidential poll, has said she would announce at a news conference whether she wants a Dalit or a non-Dalit as India’s First Citizen.

As the Congress and the BJP wait and watch, the poll arithmetic is fast transforming itself into a jigsaw puzzle.

The Congress, having expressed pique at the Left’s premature announcement of Pranab Mukherjee’s candidature, is grappling with a host of dilemmas, party sources admitted.

If not Mukherjee and Sushil Kumar Shinde, supposedly the party’s second nominee, whom would it field? Whoever the “dark horse” is, he or she must be acceptable both to the Left and the BSP, who have rarely ever seen eye to eye on anything.

The Congress’s problem is, the Left is still the United Progressive Alliance government’s biggest prop. It needs the “comrades” not just to survive but also to push through hard economic decisions, such as pension and labour reforms.

“This must be done in 2007 because 2008 will be a warm-up year for the general election. Populism will take precedence over pragmatism,” a source said.

Yet, with Dalit empowerment being the watchword, the Congress doesn’t want to do anything to anger Mayavati.

The chief minister has a reputation as a political maverick, ever ready to switch sides.

Some in the UPA are sure she would only back a candidate from a “secular” party, but this seems a fond dream because secularism has never been an issue with the BSP. Mayavati was thrice chief minister with BJP support.

The Congress also knows that the BSP might reap a rich haul of seats in the 2009 Lok Sabha elections. That would make it a crucial player in a Parliament that is expected to be a fractured one.

The BJP had earnestly prepared itself for a contest. It lags the UPA by 73,641 votes in the electoral college, while the so-called third front — a motley group of regional and caste-based parties — and the unattached outfits together account for 229, 280 votes.

The BJP was hoping to work on “vulnerable” parties like the Samajwadi Party (60,532), Telengana Rashtra Samiti (7,388) and Independents (33,043). This group also includes the BSP with its 61,319 votes.

Like the BSP, the Samajwadi has kept its cards close to its chest, with general secretary Amar Singh sending out contrary signals.

One day Amar indicates willingness to go with the Left without a commitment to back a Congress nominee; the next he is happily lunching with Mamata Banerjee or meeting George Fernandes, who are working on the NDA’s behalf.

The BJP may not pluck up the courage for a fight if the numbers don’t add up.

Some in the party believe it would be politically expedient to back a “consensus” UPA candidate if the ruling alliance returns the “favour” by allowing B.S. Shekhawat to stay Vice-President. But the “formula” is still being debated, BJP sources said.

The last piece in the puzzle is the Left. “Having gone public on Mukherjee, will it show the same enthusiasm for another Congress candidate?” a source wondered.