THE UK Government has refused to ban companies which were involved in blacklisting workers from gaining public sector contracts.

The SNP's workers' right spokesman, MP Chris Stephens, accused Tory ministers of "handwringing" after they refused to ban blacklisters.

"It remains a sign of bad faith that the perpetrators of blacklisting have access to public money to boost their profits," he said.

Stephens wrote to the UK's Minister for small Business Margot James MP asking for sanctions to be imposed against firms involved in the practice.

However, the Tory minister responded that she would not intervene to ban firms that were involved in the blacklisting of trade union activists.

The row came as a £29 million contract to refurbish Big Ben was awarded to construction firm Sir Robert McAlpine Ltd, which was forced to apologise and pay compensation totalling about £75m to 771 blacklisted workers last year after legal action.

In her letter to Stephens, the minister, said: "The Government takes the issue of blacklisting seriously and has an appropriate legislative framework in place for tackling it.

"Under UK public procurement rules, which implement EU rules, public procurers may already exclude a supplier on grounds of certain past behaviour like grave professional misconduct.

"It up to individual contracting authorities to apply these measures and take steps to be confident in the current practice of their contractors."

Stephens said the UK government was washing its hands of responsibility.

He said: "This is handwringing at a time when MPs have major concerns about the potential awarding of contracts such as the reconstruction of Big Ben and when serious allegations are being made by trade unions that blacklisting continues to this day.

"It's completely unacceptable that the UK Government should leave the contracting authorities," he said.