I have recently been appointed as Parliamentary Private Secretary (PPS) to Greg Clark, who is the Minister for Decentralisation & Planning in the Department of Communities & Local Government and also has a cross-government responsibility as Minister for Cities.
PPSs are regarded as members of the Government for the purposes of collective responsibility - in other words, they are expected to vote with the Government - but they are not Ministers and don't receive any additional salary on top of their pay as MPs. The role involves supporting your Minister and acting as his or her eyes and ears in the House of Commons. Essentially it is a very small first step up the greasy pole.
I am delighted to be working for Greg, who I have known for years and think is one of the most able Ministers in the Government (he would, I am sure, have been a Cabinet Minister had the Conservatives won an outright majority at the last Election - he was a member of the Shadow Cabinet beforehand and was one of those to miss out as a result of the need to give some Cabinet roles to the Liberal Democrats).
I've had to stand down as a member of the Executive of the 1922 Committee and the Science & Technology Select Committee, both of which I have really enjoyed, but the appointment shouldn't have a detrimental impact on the work I do as your local MP - indeed, if anything it should help a little as the things Greg is responsible for are very relevant to Croydon.