When I wake up overnight needing to pass urine I get up to go to the toilet and start leaking urine straight away. This never happens during the day.
How long have you been experiencing this, is it a new occurrence? It is common for medication to cause leakage during the night, are you on any medication that could be causing this?
I would recommend watching your fluid intake in the evening before bed time, and cutting down on irritants such as sugar and caffeine. If lifestyle changes do not work, I would recommend visiting a Doctor for a blood test and a scan to look for any possible causes. You could have a lack of the anti diuretic hormone, which causes the body to create less urine at night.
Have you had accidents in the night? I would recommend using a slip (all in one) product if you experience leaks.