Instead, the source said that the Prime Minister was currently planning an “emblematic” announcement to soften the blow of soaring energy bills in April when the price cap is lifted.

Despite Tory backbenchers urging Mr Johnson to postpone the 1.25 percentage point rise in NICs, figures close to the Prime Minister are understood to have urged him to focus on the long-term benefits of holding firm.

The argument being made is that once the immediate cost of living crisis has subsided, Mr Johnson will gain more electorally from tackling NHS backlogs and delivering a sustainably funded social care system.

Despite No 10’s apparent resolve, business leaders renewed calls on Friday for the Chancellor to “think again” about proceeding with what they warned would be a damaging tax blow.

Jonathan Geldart, the director general of the Institute of Directors, warned that the move to increase employer and company NI contributions by 1.25 percentage points would have “a negative and significant” impact on its members and the wider economy.

Mr Geldart said: “In the last few months, the case against the tax rise has, to my mind, only become stronger. That’s why we are urging the Chancellor to think again about raising national insurance contributions and are asking for the opportunity to discuss the matter as soon as possible.”

The IoD, which represents 20,000 members, launched a petition against the tax rise this week, which has gained 1,000 signatures and adds to the momentum of opponents as Britain faces a cost of living crisis.