Figures released by the Electoral Commission show the former Conservative Co-Treasurer, Peter Cruddas gave the Conservatives £215,244 between January and March.
Mr Cruddas resigned from his post in March after undercover reporters from the Sunday Times filmed him suggesting major donors could gain access to No 10 and have ideas fed into policy committees.
Peter Cruddas gave the sixth biggest donation to a political party overall in the first three months of this year.
Of the other five donations, four were from trades unions to the Labour Party, one was from the Cooperative Group to the Cooperative Party, which stands candidates with Labour.
Top of the list is the union Unite, which gave the Labour Party £918,568. Unison handed over £547,901.
Overall, the Conservatives continued to receive the most money in donations - a total of £4,086,097.
But Labour was close behind, bringing in £3,452,441.
The Liberal Democrats raised £606,724.
Declarations to the Commission show public funding for the period came to just over £850,000.
The parties owed £14,634,772 between them in outstanding loans.