Jeremy Corbyn's flagship anti-discrimination pledge will cost British taxpayers "a net minimal cost" if the Labour leader gains power, according to his campaign team.

IBTimes UK pressed the left-winger's spokespeople on the issue after Corbyn committed to boosting funding for the Equalities and Human Rights Commission during the launch of his bid to retain the Labour leadership on 21 July.

The veteran parliamentarian said he would fund the watchdog to "monitor employers' equality pay audits, to take action where required to eradicate discrimination and to fine employers that do not provide them."

He added: "Many employers wouldn't want to discriminate against their staff, such discrimination holds back companies and our economy.

"If our economy is to thrive, it needs to harness the talents of everyone. So this is about making our economy stronger, the workplace fairer [and] reducing the discrimination that holds people back."

The costing of the pledge was unclear, with no approximate figure being provided by Corbyn or his team. Spokespeople for the Labour leader later told IBTimes UK: "We envisage a minimal net cost."

The promise came after Corbyn also said he would force employers with more than 21 staff to publish equality pay audits to detail remuneration levels, grades and hours of every job alongside data on recognised equality characteristics "because it is not only women who face workplace discrimination, but disabled workers, the youngest and oldest workers, black and ethnic minority workers."

Corbyn, who secured almost 60% of the vote in Labour's 2015 leadership election, faces a challenge from former shadow cabinet minister Owen Smith. The pair will go head-to-head for next two months until the winner of the contest is announced in Liverpool on 24 September.

Smith, a former radio producer and PR chief for pharmaceutical giant Pfizer, has unveiled a range of policies as part of his campaign. The Pontypridd MP has promised to re-write Clause IV of Labour's constitution to put fighting inequality at the centre of the party's mission.

The 46-year-old has also committed to introducing a 'War Powers Act', to allow MPs to "properly scrutinise the government of the day", as well as a second referendum on the EU to "ratify Brexit".

The latest opinion poll from YouGov for The Times, of more than 1,000 Labour members between 15 and 18 July, put Corbyn on 54% on first preference votes, with Smith on 15%. The Labour leader recently revealed more than 183,000 people paid £25 to become a Registered Supporter and have a vote in the election.