Last week it emerged that The Daily Telegraph and Channel 4’s Dispatches had filmed Straw and Rifkind meeting with undercover reporters posing as a fake Hong Kong-based comms agency called PMR, asking the politicians to use their positions to benefit the firm in exchange for money.
Both have denied any wrongdoing.
Social media monitoring firm Talkwalker has conducted sentiment analysis to assess how social media users are reacting to the party leaders and politicians involved.
Since the incident, negative sentiment towards Cameron on social media has risen from 40 per cent to 65 per cent and is now 74 per cent in references that mention Rifkind or hashtags associated with corruption. Mentions without reference to Rifkind are 45 per cent negative and 10 per cent positive.
Meanwhile positive sentiment towards the Prime Minister has dropped from nine per cent to two per cent.
Labour party leader Miliband has suffered a similar blow, with negative sentiment rising from 34 per cent to 78 per cent in references that also mention Straw or emotive hashtags. Positive sentiment has dropped from 15 per cent to one per cent.
Sentiment mentioning Miliband but not Straw is 38 per cent negative and 15 per cent positive.
Rifkind and Straw have attracted less negative social sentiment than their party leaders, with negative mentions reaching 55 per cent for each of them.
Since the scandal broke last week, Straw and Rifkind have been suspended by Labour and the Conservatives respectively.
The most common hashtags surrounding the issue are #cashforaccess #greed, #corruption and #sleaze.
Robert Glaesener, Talkwalker chief executive, said: "Despite attempts by Mr Cameron and Mr Miliband to isolate the toxic cash for questions issue, the damage had already been done. Negative sentiment towards them both has increased day on day since the news broke.
"Negative sentiment towards all four politicians outweighs neutral sentiment significantly, suggesting that people are more angry than apathetic about the issue".