In the case of the survey you're talking about, it looks like the
approach is to ask (in effect) "Do you agree with our party policy on
this issue?", and to provide free space for you to elaborate if you want
to.

It was more 'don't you think the government's policy is rubbish' and quoting carefully selected statistics to influence your answer.

Having said that, the first half of the questionaire had a lot of sensible questions on what was important locally and had no bias of any kind.