The umbrella body established the scheme to enable small charities with low incomes to attend the conferences. The initiative covers the cost of travel and hotel accommodation.
Charities must have incomes of less than £100,000 in order to qualify for a bursary. The 15 winners of this year's bursaries all have incomes of between £2,000 and £10,000.
Those involved this year will attend either the Liberal Democrat conference in Bournemouth, which begins this weekend, the Labour conference in Manchester or the Conservative conference in Birmingham.
The bursary winners will participate in round-table discussions at the conferences. Guest speakers will include Susan Kramer, Liberal Democrat spokeswoman on the Cabinet Office, Phil Hope, Minister for the Third Sector, and Greg Clark, shadow minister for the third sector. The discussions will focus on issues such as lobbying by charities and the effects of the credit crunch on charitable giving.
The charities attending the Liberal Democrat conference are the University of the Third Age, Southall, the Communities Empowerment Network, Growing Through, Ménière's Society and the Angioma Alliance.
The Labour Party conference will be attended by Zindgani, Bacup and Stacksteads Tenant Management Organisation, Match, Survivors of Depression in Transition and What About The Children?
The charities attending the Conservative Party Conference are Lelant Village Hall, Right from the Start, the Community Culture Group, Dream Africa and the Fielding Recreational Trust Fund.