The number of companies giving to the Conservatives in the last financial year was still far lower than before the general election, the list will show, and many of those who have remained have cut their donations.
The news follows a revelation in yesterday's Independent that Mr Ashcroft has been rejected for a peerage amid criticism about his tax-exile status.
William Hague was jubilant yesterday at an overall increase in the number of Tory donors giving more than pounds 5,000. But party officials admitted that regaining the support of business was still a problem. They still want to broaden further their base of support, thus lessening the influence of rich men who have kept them afloat over the past two years.
The Conservative leader backed Mr Ashcroft and said the Tory accounts to be published shortly would show progress. "There will be many, many more donors from many different sources and a much wider range of donor," Mr Hague said.
Corporate donation figures for 1998-99, compiled by Labour Research, show that the cereal firm Weetabix cut its donation to the Tories from pounds 274,000 in 1997-98 to pounds 25,000 in 1998-99.
Tarmac, the construction giant, reduced its gift to pounds 40,000 from pounds 50,000 the previous year, while the property company Slough Estates cut its gift from pounds 42,000 to pounds 36,000, and the engineering firm IMI paid pounds 25,000 compared with pounds 40,000 the year before.
Among the biggest corporate donations to be disclosed by the Tories is pounds 100,000 from Wittington Investments, the vehicle of the Irish businessman Garry Weston, which owns 90 per cent of the Fortnum and Mason store. The company made an identical donation in 1997-98.
Labour Research found that the number of company donations to the Tories dropped from 351 at the time of the 1992 election to 120 in 1997-98, with many deserting because of the party's anti-euro stance. However, the Birmingham steel firm Ash and Lacy has been loyal, despite the pro- European stance of its group managing director, Howard Marshall. The firm gave pounds 7,000 in 1997-98 and pounds 5,000 in 1998-99.
Among the individuals who gave to the party were Mr Ashcroft, who is probably the biggest single donor, and the Monaco-based Scots businessman, Irvine Laidlaw, who gave pounds 200,000.