Tax rises in the Budget have made it more difficult for firms to “take a chance” on hiring people, according to one of Britain’s most prominent business groups.

In a speech at its annual conference on Monday, the boss of the Confederation of British Industry (CBI) will say the changes are undermining investment.

Rain Newton-Smith will suggest businesses across many sectors are “being hit by a tough trading environment that just got tougher” due to changes in National Insurance contributions (NICs) and inheritance tax.

The government said “difficult choices” had been made in a bid to “repair the public finances”, but that it was determined to work with firms.

In her first Budget as chancellor last month, Rachel Reeves announced a near-£70bn increase in public spending, partly funded by increases in taxes on businesses.

While rises in the minimum wage and workers’ rights reforms have been praised by unions and workers’ groups, bosses have hit out, saying that their businesses are being weighed down multiple changes at once.

In her speech to the CBI’s conference, Ms Newton-Smith will argue that “tax rises like this must never again simply be done to business”.

She will also point to a recent survey by the group, which found almost two-thirds of 185 companies who responded think the Budget will damage UK investment.

Ms Newton-Smith will also say that profits “aren’t just extra money for companies to stuff in a pillowcase, but the key to investment”.

“When you hit profits, you hit competitiveness, you hit investment. You hit growth,” she will say.

Last week, a group of major retailers, including Tesco, Amazon and Next, wrote to the chancellor to warn her of the impact tax changes would have.

Firms such as Sainsbury’s and Marks & Spencer have said they will face a huge jump in costs and they may need to increase prices for customers.

However, critics have said that asking multimillion pound companies to pay more in taxes was one of the fairer ways to improve funding for services like the NHS.

“No-one is questioning that we need to see the tax rises to really help fund our public services,” Ms Newton-Smith told the BBC’s Today programme.

But she said that firms had been taken aback by the lowering of the threshold for the payment of National Insurance, and that the pain was “really serious”.

In her speech she will urge the government to consider a number of reforms to improve economic growth, such as giving companies more flexibility around how they spend money using the apprenticeship levy.

She will also say that the chancellor should look at updating business rates for commercial property, as well as simplifying the planning system.

According to reports on Monday, the chancellor will use an opportunity at the conference to respond to criticism of Labour’s first Budget in 14 years.

The Guardian suggests she will tell business leaders that they have offered “no alternative” to her plans, and that it was necessary to “wipe the slate clean” following the General Election.

During the campaign period, Labour had promised that “working people” would not see higher taxes in their payslips.

A government spokesperson said that the pledge meant that it had had to take “difficult choices to repair the public finances and to put public finances on a firmer footing”.

“Despite the difficult inheritance, the government is determined to go for growth and to work in partnership with businesses to invest in Britain’s future so we can make every part of the country better off,” they added.