Shrouded in secrecy and working in virtual isolation, Finance Minister P. Chidambaram and his team have been burning the midnight oil, probing countless reports and crunching numbers to solve the budgetary jigsaw puzzle ahead of the big day Monday.

The expectations are high. Some analysts say that this budget will be the United Progressive Alliance government's most important policy pronouncement since the National Common Minimum Programme for governance unveiled last May.

"In his last budget speech, Chidambaram had said in no uncertain terms that he would introduce comprehensive reforms in his next budget," said D.H. Pai Panandikar, a noted business economist and president of RPG Foundation.

"Tax reforms will be a priority. After all, this finance minister is a reformist. He knows that there is much expectation. He won't remain quiet. One can also expect radical measures on infrastructure development," Panandikar told IANS.

The task before 'Team Chidambaram' is four fold - reduce deficits, reform the tax administration, provide money for areas ranging from infrastructure to social development and show that the government has ample appetite for reforms.

Little wonder Prime Minister Manmohan Singh - who has held at least six formal sessions with his finance minister on the budget besides several informal ones on the margins of other meetings - is tapping every resource for this annual exercise.

From Planning Commission Deputy Chairman Montek Singh Ahluwalia to members of the Prime Minister's Economic Advisory Council, a host of experts have given their advice to shape the budget that can live up to its high expectations.

The exercise has also involved key finance ministry officials - economic affairs secretary Rakesh Mohan, expenditure secretary D. Swarup, revenue secretary K.M. Chandrasekhar, advisor Parthasarathi Shome and chief economist Ashok Lahiri.

"Normally prime ministers just have a broad outline for the budgets and leave the spade work to the finance minister and his team," an official familiar with the budget exercise said.

"But Manmohan Singh is different, having himself been a finance minister and an acclaimed one at that. Even the finance minister's speech is being examined word by word to send the right positive signals," the official added.

The preparation for the budget, in fact, started as early as in November. What is more, Chidambaram this time met not only with the usual list of trade union leaders, farmers, economists and corporates but also coalition allies.

"I am sure he will carry his political allies along this time, particularly the Left parties," said Amit Mitra, secretary general of the Federation of Indian Chamber of Commerce and Industry (Ficci).

"Though it may not be his budget strategy, the finance minister may even make some provisions - say 5-10 percent - for roll back of some proposals if the need arises to keep coalition partners happy," Mitra told IANS.

In this year's budget, Chidambaram also has to begin the process of eliminating the country's revenue deficit - the gap between what is raised in taxes and what is spent - by fiscal 2009 as required by statute.

This will be a daunting task since the government's tax receipt is sharply below targeted levels and if that were allowed to continue in the next fiscal, it will have implications on the money available for social sectors and infrastructure.

In indirect taxes, the finance minister has committed himself to reducing the country's customs tariffs to levels prevailing in Southeast Asian economies, while in direct taxes his stated objective is on simplifying the system.

"This budget is expected to be heavy on both direct and indirect tax reforms," said leading industrialist and chairman of Apollo Tyres Onkar S. Kanwar. "Unlike the last budget, the finance minister has had time to look at issues closely."

Industry and economists alike also expect the budget to unveil some measures that will show continuity in the economic reforms process, even though they may not be related to the budget.

In the last budget, Chidambaram had announced easing on foreign equity limits in telecommunications, civil aviation and insurance sectors. Similar announcements are expected this year as well, especially in infrastructure sector.

"To put in a nutshell, growth will be the main driver of this budget. It will draw heavily from the bible for this government - the National Common Minimum Programme. There can be no doubt on that," Mitra said.