Mystery YouGov poll looks for Nick Clegg's weaknesses

This article is more than 9 years old
Telephone survey for unnamed client has brought objections from Liberal Democrats about loaded questions
Nick Clegg at the first leadership debate
Lib Dem leader Nick Clegg's popularity has soared in the wake of the first leaders' debate. Photograph: Ken Mckay / Independent Telvisio/EPA

One of the biggest political pollsters is conducting a survey of voters to establish the best lines of attack on the Liberal Democrat leader Nick Clegg in the wake of his meteoric rise since last week's leadership debate.

YouGov, which is running a daily opinion poll for the Sun, has been asking voters what would be most likely to put them off voting for the Liberal Democrats.

The poll was commissioned privately and YouGov has refused to confirm the identity of its client. But it did confirm that it polls for the Labour party, the Conservatives and the Scottish National party.

One of the surveys being connducted by telephone as recently as Sunday, and subsequently leaked on the internet, asked 17 questions about the Liberal Democrats and asked people to rate a series of statements according to how likely they were to affect their voting intentions.

One statement read: "Nick Clegg says the other parties are to blame for the MP scandals, he has taken money from a criminal on the run, many of his MPs have been found guilty of breaking the rules and his own party issued guidance on how to fiddle the expenses system."

An aide to Clegg objected to the language in the statement. "If this report is true it is just another example of the desperation of whoever is organising these things. They clearly don't want to see any change and will use any tactics to attack us.

"These people should work out some positive policies and learn to communicate them."

YouGov rejected accusations being made on some blogs that it was asking leading questions. It said Sunday's survey on the Liberal Democrats was entirely separate to its regular polls for the Sun, the Times, the Sunday Times and the News of the World.

Anthony Wells, the YouGov political analyst running the poll over the weekend, said: "We test lots of messages and ask people in different ways to see which are the most effective ways to sell an idea. I cannot say who the client is but this was not part of the work we do for News International." He would not confirm or deny the exact wording of the questions or reveal what other messages were being tested.

The Liberal Democrats' soaring poll ratings in the wake of the leaders' debate have been attributed to Clegg's performance and the message that his party offers an alternative to what he calls the "old politics" of Labour and the Tories.

Meanwhile, the party has been allowed to keep £2.4m donated by the company of the convicted fraudster Michael Brown. It was given before the 2005 election when Charles Kennedy was leader.