By Wednesday evening we will know the details of Chancellor of the Exchequer Gordon Brown's first Budget, and Jeremy Peat, the Royal Bank of Scotland's chief economist, sees no reason for the Chancellor to be too tough.

''There are no reasons on fiscal grounds why the Budget should be particularly harsh. A little belt-tightening might be required, but if so, it should be one notch rather than two or more. Consumer spending is growing too fast and he might put up taxes in an effort to dampen this down, and at this stage in the political cycle it makes sense for him to have some painful measures sooner rather than later.

''However, there are no black holes in the public finances, and we know that he is committed not to extend the coverage of VAT or raise the rates of personal tax. I would be surprised if he did anything to discourage long-term savings, so I would not expect to see major changes to incentives for additional voluntary contributions (AVCs) or personal equity plans (Peps), which encourage people to take responsibility for their retirement.

There is the question of the Chancellor's personal style, though, and that gives Mr Peat some disquiet. He says: ''The Chancellor likes being radical, and that makes me nervous that there might be some change to personal or corporate taxation.''

Donald Adamson, head of taxation at KPMG, also has some concerns. He has topped up his own personal pension and advises others to do the same to reduce the effect of tax relief being restricted to the basic or lower rate.

He says: ''There might also be changes to capital gains tax, with two rates being introduced. This would allow the Chancellor to discriminate against shorter-term gains. The allowance for CGT might be reduced.

He adds: ''As far as inheritance tax is concerned, there might be a tightening of the rules for partially exempt transfers, whereby people can reduce their estate by giving assets away and as long as the donor survives for seven years, tax can be avoided. The rules for gifts into discretionary trusts might also be made tougher.''

The tax credit on dividends might be reduced, so Mr Adamson advises directors of private companies to pay dividends before July 2.

''I would be surprised if there were many changes to the taxation of company cars, as that has already almost been done to death, but there could be some changes at the margins.

''I would not be surprised to see national insurance contributions being extended to perks such as private health care and mobile phones,'' Mr Adamson says.

Ken Aitken, who is a tax partner with accountancy firm Scott-Moncrieff Downie Wilson, expects Gordon Brown's first Budget to be memorable.

He explains: ''I will be very surprised if Gordon Brown does not want to leave his mark. The Chancellor has already been in the limelight and is part of a Government which has been very active. Everyone is waiting with baited breath.''

Mr Aitken expects that there will be a drive by the new Chancellor to close off tax loopholes, and he expects tightening in the regimes for the taxation of capital gains and inheritance.

''There is a school of thought that we all came into this world with nothing and there are no good reasons for leaving things to our offspring. I would not be surprised if the allowances for inheritance tax and capital gains tax were restricted.

''I think that he might also take the opportunity to integrate income tax and National Insurance to some extent, and I would welcome this if the effect would be to reduce administration.''

With the Prime Minister showing such passion for environmental issues, it looks as if it could be a tough Budget for the motorist and the duty on petrol must be a tempting target for Mr Brown.

The Chancellor has made it known that he will not be drawing strength and inspiration from alcohol during his speech. Ken Clarke sipped a glass of malt whisky during his last Budget, but Mr Brown will, in the Presbyterian tradition, restrict himself to mineral water.

For the rest of us, it looks as if it might be a good idea to stock up with tobacco and alcohol. The alternative might be to take a leaf from Mr Brown's book and abstain.