Oxford Capital, a firm that runs Enterprise Investment Scheme (EIS) products, is consulting on making a number of staff redundant.
A total of 14 staff at the firm's offices in London and Oxford have been informed of a consultation designed to make some of them redundant.
The number of people investing in EIS has fallen steadily since the government tightened the rules on the types of companies that qualify for EIS tax relief.
But Oxford Capital stated the rules were not directly to blame for the looming redundancies.
A representative said: "We’ve reluctantly entered into a consultation period with 14 members of our staff which may result in redundancy for some of our workforce of 41 people.
"Over the last three years we have been reorganising the business to make it more competitive in the current market. This is not directly linked to the new EIS rules."
Investors in EIS qualifying companies can receive a tax break of as much as 50 per cent of the amount invested, with any income and capital gains exempt from tax.
The rules changed in 2015 which led to the number of investors into EIS products falling from 3,545 in the 2015/16 tax year, to 3,470 in the 2016/17 tax year.
In 2017 they were further tightened by chancellor Philip Hammond, who excluded companies that are "asset based" in favour of companies that are knowledge based.
The government initially introduced a seven year age limit for companies to qualify for EIS, and banned any one company from receiving more than £12m from investors.
In addition, companies wishing to receive EIS funding must now show that capital is genuinely at risk. This came after the Treasury had previously stated it felt too many EIS funds were engaged in "capital preservation" investments, which carried little risk and so did not justify the tax breaks investors received.
Alex Davies, founder of tax efficient investment specialist Wealth Club, said as many as 50 per cent of the companies that may have qualified for EIS tax relief before would not qualify under the new rules.
Ingenious, a company that invests in media assets, was forced to pull its fundraising in February, after deciding that the types of assets into which it wished to invest would unlikely be approved for the EIS tax breaks.
Media is one of the three areas Oxford Capital lists on its website as being its areas of specialism. The others are infrastructure and technology.
Richard Hoskins, a partner at tax efficient investment specialist Kin Capital, said: "Oxford Capital is one of a number of firms that had heavy exposure to the renewables sector, they grew very fast from investments in infrastructure, but the rule changes mean the music has stopped.
"I'm afraid I think there will be more bad news. Demand overall is lower for EIS products. There are a lot of managers chasing deals rather than just chasing the tax breaks, and that means there are a lot of managers chasing the same deals.