More Conservative supporters complained en masse about the BBC’s news coverage during the general election than Labour supporters, according to a Guardian analysis, suggesting Tories are more likely to take the time to write a stern letter of complaint.

While many on the left of politics, including prominent members of the shadow cabinet, claimed the BBC’s political coverage was pro-Tory, the broadcaster’s complaints log suggests the corporation was inundated with feedback from members of the public who felt its coverage was skewed in favour of Jeremy Corbyn’s party.

One possibility is that while leftwing activists complain publicly on social media, those on the right are more likely to send in formal complaints and try to exert pressure using the BBC’s official processes.

The BBC receives thousands of pieces of feedback a week, but only regularly publishes details of individual programmes that collectively receive more than 100 complaints for a specific reason.

Of the 23 complaints relating to party politics that hit that threshold since mid-October, the vast majority argued that the BBC in some way showed bias in favour of Labour on its election-related output such as the Andrew Marr Show, Radio 4’s Today programme and Newsnight.

Only six of the most popular complaints suggested the corporation was biased in favour of the Conservatives. These related mainly to a handful of specific high-profile incidents such as the use of old footage of the prime minister laying a wreath at the cenotaph or the editing out of the audience laughing at Boris Johnson.

Many mass complaints to the BBC are driven by social media campaigns. It is possible that while Labour supporters, who tend to be younger, are likely to complain about alleged bias after seeing clips circulating on social media, Conservative supporters are more likely to be in the older demographic who watch televised news programmes shows live.

The show to attract by far the most complaints was an eve-of-poll edition of the Andrew Marr Show featuring Boris Johnson, scheduled at the last minute following the terrorist attack on London Bridge after he had refused an interview with Andrew Neil. It attracted complaints from 12,172 viewers who felt Marr was biased against Boris Johnson.

A BBC spokesperson said the data gives only a partial overview of the feedback it receives. They said: “The BBC receives tens of thousands of comments, appreciations and complaints from its audiences each year. We are required by Ofcom to report specific types of complaint in our fortnightly reports but it would be wrong to assume that analysing these reports gives a complete or accurate picture of all audience reaction.”

Analysing the complaints logs for the rest of 2019, however, shows a similar pattern. Mass complaints alleging the BBC is biased in favour of either Labour or the remain campaign consistently outnumber those alleging the broadcaster is biased in favour of the Tories or Brexit by more than two to one.

The BBC was at times flooded with complaints from opposing sides claiming the same programme was biased. One edition of the Andrew Marr Show broadcast in May attracted 1,128 complaints from the public. Some claimed the programme exhibited clear bias against Nigel Farage or against Brexit and others claimed the opposite.

The complaints logs also give insight into what riles some segments of the British public. In September, 178 people complained to the BBC about alleged “bias against Brexit/bias in favour of LGBTQ rights” on Last Night of the Proms. Some viewers has taken offence at audience members with EU flags and the US singer Jamie Barton waving a rainbow flag.