Media playback is unsupported on your device Media caption The BBC's Clive Coleman says the number and nature of questions was "quite unusual"

The jury trying ex-minister Chris Huhne's former wife Vicky Pryce has failed to reach a verdict on a charge relating to speeding points she took for him 10 years ago.

On Tuesday, the jurors had posed 10 questions to the judge, Mr Justice Sweeney, prompting him to raise concerns about their "absolutely fundamental deficits in understanding" of their role and the trial process.

Here are the questions and the answers he gave:

1. You have defined the defence of marital coercion and also explained what does not fall within the definition by way of examples. Please expand upon the definition, specifically "was will overborne". Provide examples of what may fall within the defence, and does this defence require violence or physical threats?

Mr Justice Sweeney said it did not require violence or physical threats and meant a woman was so affected by pressure from her husband that she was "impelled" to commit an offence and truly believed she had no real choice.

He added: "The words are relatively straightforward English words which the law does not permit me to go beyond further than I have by way of clear illustration in these directions."

2. In the scenario where the defendant may be guilty but there is not enough evidence provided by the prosecution at the material time of when she signed [the penalty notice letter] to feel sure beyond reasonable doubt, what should the verdict be: not guilty or unable/unsafe to provide a verdict?

No recorded answer

3. If there is debatable evidence supporting the prosecution's case, can inferences be drawn to arrive at a verdict? If so, inferences/speculation on the full evidence or only where you have directed us to do so, eg circumstantial evidence, lies, failure by Vicky Pryce to mention facts to the police.

The judge said no, adding: "The drawing of inferences is a permissible process, speculation is not."

"You must not speculate and you could not draw safe inferences from debatable evidence because you need to be sure that your inference, you reasonable common sense conclusion, is correct.

"In this case, the evidence on which the prosecution relies is largely undisputed."

4. Can you define what is reasonable doubt?

Mr Justice Sweeney said: "A reasonable doubt is a doubt which is reasonable. These are ordinary English words that the law doesn't allow me to help you with beyond the written directions that I have already given."

5. Can a juror come to a verdict based on a reason that was not presented in court and has no facts or evidence to support it either from the prosecution or defence?

"The answer to that question is firmly no," said the judge. "That is because it would be completely contrary to the directions I have given you for anyone to return a verdict except a true verdict according to the evidence."

6. Can we infer anything from the fact that the defence did not bring witnesses from the time of the offence such as au pair, neighbours?

7. Does the defendant have an obligation to present a defence?

To these two questions Mr Justice Sweeney told the jurors: "There is no burden on the defendant to prove her innocence. On the contrary, there is no burden on the defendant to prove anything at all."

He added: "You must not as I have now emphasised many times, speculate about what other witnesses will have not been called might have said or draw any inferences from their absence."

8. Can we speculate about the events at the time that Vicky Pryce signed the form, or what was in her mind at that time?

"The answer to that is an equally firm no," Mr Justice Sweeney said. "There's a difference between speculation, which is not permitted, and inferences."

9. Your honour, the jury are considering the facts provided but have continued to ask the questions raised by the police. Given the case has come to court without answers to the police's questions, please advise on which facts in the bundle the jury shall consider to determine a not guilty or guilty verdict.

Mr Justice Sweeney said: "You decide the case on the evidence. That means it is for you to review all of the evidence and decide which of it you consider to be important, truthful and reliable, and then decide what conclusions, common sense conclusions, you can safely draw by way of inference from that evidence."

10. Would religious conviction be a good enough reason for a wife feeling that she had no choice, ie she promised to obey her husband in her wedding vows and he had ordered her to do something and she felt she had to obey?

"This is not, with respect, a question about this case at all," said the judge. "Ms Pryce does not say that any such reasoning formed any part of her decision to do what she did and the answer to this question will therefore not help you in any way whatsoever to reach a true verdict in this case.

"I must direct you firmly to focus on the real issues in this case and thereby to reach a true verdict according to the evidence."