Outside of whether they will give you the role, the civil service will unlikely be able to match your pay unless you bring some specialised skills like finance/economics/tech/cyber security etc. Even then, you need to be Director level, and a seasoned Director.

Minister Chan shared in Parliament recently that civil service senior management (i.e. Directors and above) earn between 200 to 260k. 200k is probably for a young Director, 40-45 years of age. So at your current wage you are already earning maybe a 50s Director age.