To ask how to cause maximum bother for the PM

[Fieldofbrokenpromises]

I received a letter from the Prime Minister, he claims to want to hear from me.

He was kind enough to enclose a reply paid envelope, and a ridiculous "survey".

I wonder if filling the envelope with something inert but heavy might cost them more than if I just write back that I am sick of this corrupt tax-dodging venal scumbag government?

I used to know someone who claimed to have worked in an office where they opened these responses - she claimed someone taped the letter to a brick, and also someone filled it with a bag of dog shit.
I doubt these were true and I don't want to be unpleasant to the poor souls opening the letters, but if there is a way to cost the Conservative Party extra I'd love to do it.

If it's a survey asking for your opinion, why don't you fill it in and return it? Tell them what you think?

@Fieldofbrokenpromises a great way to think of the public that cover the costs of your planned activities

This

Put chili powder in his underpants?

I've got a Labour MP who is likely to be reelected. I intend to canvass against the sitting Tory MP in either my neighbouring constituency or in the one where I used to live.

I'd hope that would be more effective than looking for ways to increase the bill for the Conservatives' stamps.

Well this the more adult way to try and create change .

And that will do what exactly ?
Apart from costing them postage?

We got one too.
The questions are heavily weighted pro the Conservatives.
I am happy to fill it in.
However, I object to giving my personal on a form. Have they never heard of identity fraud?
I feel it is an invasion of my privacy and undemocratic to ask who I have voted for in the past and my voting preferences for the next election.

Judging by the current state of the Royail Mail they’ll receive it after the next election.

We don’t seem to have a post service anymore.

"Rishi Sunk". Hopefully a prophetic name, OP.

Instead OP prefers to start a mumsnet thread about filling in the survey

i suspect in the end the survey will be recycled anyway!