The AIC and EIS Association are calling for greater flexibility for VCTs and EIS in this year's budget.
Both industry representatives stress the importance to the UK economy of making the vehicles more attractive to investors and for these changes to be made quickly.
In its submission to the Treasury the AIC is calling for an increase in the size of the company in which a VCT is invested with a view to increasing this level from £7m to £15m.
The AIC is also calling for greater flexibility around the 50 employee limit for VCT qualifying companies.
Spokesperson Annabel Brodie-Smith says: "VCTs are an established, mature investment vehicle with proven expertise for investing in small companies.
"In our opinion, and given the current economic climate, it would make sense for the government to continue to support VCTs and consider ways to increase this support if possible."
Meanwhile, the EISA is calling for an immediate increase in income tax relief to 50%, the permission of loan stock investment, as with VCTs, and for the Treasury to allow follow-on funding.
In EISA's introduction to its budget submission, the association says due to a combination of factors EIS' appeal to investors has been greatly reduced and for the sake of the scheme and the wider UK economy the government needs to act now to save it.
