Diane Abbott has said Fiona Bruce was “clearly repeating Tory propaganda” and rejected the BBC’s response after the Question Time host misstated Labour’s position in the polls, as the shadow home secretary shows no sign of backing down in her row with the corporation.

Labour has formally complained to the BBC over Abbott’s treatment on last Thursday’s episode of the programme. Bruce wrongly backed claims by the panellist Isabel Oakeshott that the Conservatives were leading in the polls, amid disputed claims that Abbott was also mocked during the programme’s warm-up.

The BBC has admitted that Bruce made a mistake on the polling, accepting that some polling companies show Labour is neck and neck and “we should have made that clear”. However, it has not responded in detail to claims about what was said during the warm-up, despite calls from Labour to release any footage held by the broadcaster and issue an on-air apology.

Abbott said on Monday that the BBC’s response was not good enough, adding: “Fiona Bruce was clearly repeating Tory propaganda that Labour were behind in the polls. If she had said behind in one poll, that would have been a different matter. This is not an apology and does not address all of the issues that have been raised.”

The row also highlights the extent to which viral clips and news stories generated by Question Time can reach substantially more people than those who watch the actual programme.

While the BBC One programme attracted 2.6 million viewers for its live broadcast on Thursday night, according to official figures provided by overnights.tv, the subsequent row and criticism of the BBC is likely to have reached a far larger audience, aided by the mobilisation of Labour’s online campaign machine.

Although the view-counts are measured in different ways, one video of Abbott’s appearance published by the campaign group Momentum has been seen 1.4m times on Twitter, while another clip posted on the group’s Facebook page has 445,000 viewers.

Combined with dozens of viral news articles and other videos of Abbott’s treatment on the programme, millions of people who would never have seen the original programme are likely to have seen criticism of the BBC’s current affairs output.

Several audience members at the programme’s filming in Derby claimed on Twitter that the audience booed Abbott during the warm-up and her past relationship with the Labour leader, Jeremy Corbyn, was mocked. Several of the claims were made by Jyoti Wilkinson, who works for Derby North Labour MP Chris Williamson, who said the “carefully selected audience guffawed in delight as they had been given licence to air their bigoted views in public”.

Abbott’s office previously said it was relying on third-party reports of what took place in the warm-up, as her team were not present when some of the comments were allegedly made.

Last week it issued a statement claiming the programme was legitimising racism.