So the interview was successful! Now for the awkward part, resigning from the company you have worked for an age is always difficult but always start by asking why you wanted to leave them in the first place? Remind yourself that the decision is about you and not them. That will focus you and prepare you for the potential counter offer which these days occurs more than ever. This is always indicative of a client firstly protecting themselves and has little or no bearing on you in the slightest.
So how do you deal with this, well firstly ask yourself why it took your decision to leave for them to finally realise it was time they looked after your career? Secondly ask if they are looking after you or simply protecting themselves with the continuity of your position and of course saving themselves recruitment fees and having to train someone new to perform your role at the same time. Underneath is a guide outlining this in more detail and preparing you to answer any questions which may arise.