Boris Johnson has been accused of backtracking on a promise to boost workers’ rights after leaving out landmark reforms to zero-hours contracts and the gig economy from the Queen’s speech.

Employers’ groups and trade unions said the prime minister risked “levelling down on jobs” after the setpiece event used to open parliament did not include proposals for an employment bill among his government’s priorities.

First pledged in December 2019, the bill was supposed to be the government’s main vehicle for raising workplace protections after Brexit while also acting to safeguard gig economy workers from abusive employers and exploitative contracts.

Frances O’Grady, the general secretary of the TUC, said the government was rowing back from its commitments at a pivotal moment for workers.

“This pandemic has brutally exposed the terrible working conditions and insecurity many of our key workers in retail, care, and delivery face,” she said. “We need action now to deal with the scourge of insecure work – not more dithering and delay.”

Warren Kenny, the acting general secretary of the GMB union, said workers had been “fobbed off repeatedly” by ministers promising to boost employment protections, leaving bosses free to use underhand tactics with impunity.

“Warm words on workers’ rights are betrayed by this government’s abject lack of leadership. This is an historic missed opportunity at a time when unscrupulous employers are exploiting the pandemic to attack good quality jobs,” he said.

The Guardian reported earlier this year that the bill could be delayed until at least the autumn or early 2022 amid concern that ideological opposition within the Conservative party around employment rights was standing in the way of progress.

Andy McDonald, the shadow employment secretary, said leaving the bill out of the Queen’s speech was the latest example of government rhetoric not matching the reality.

Government sources suggested the pandemic was having a profound impact on the jobs market and that ministers were waiting for the right time to implement reforms to ensure the needs of businesses and workers were addressed in the post-Covid economy.

While the jobs market has stabilised in recent months as lockdown measures are relaxed, helped by the furlough scheme, redundancies rose at the fastest rate on record late last year. However, experts said boosting employment rights had been made more important during the crisis, not less.

The employment bill was also widely viewed as vital for protecting the rights of pregnant workers and improving gender equality in the UK, with campaigners hoping it would provide greater protections for pregnant women against being made redundant, address the low take-up of shared parental leave, provide neonatal leave for parents and make flexible working the default option for employees.

Caroline Nokes, the Conservative chair of the Commons women and equalities committee said the bill was necessary to have a proper focus on female employment.

“We know that women have been particularly impacted by the pandemic and the sectors that have traditionally had a huge proportion of female jobs have been very much impacted. So we need to have a focus on how we can make sure that women – as well as young people, men, older workers – find routes back into work,” she said.

Downing Street insisted the government was still committed to bringing back an employment bill. A spokesperson said: “Through this legislation we are determined to build a high skill, high productivity, high wage economy that delivers on our ambition to make the UK one of the best places in the world to work, and to grow a business.”