My understanding of tahajjud is that it is the (nafal) prayer that is prayed after one sleeps and awakes for the purpose of prayer:
They arise from [their] beds; they supplicate their Lord in fear and aspiration, and from what We have provided them, they spend. (32:16)
and it is also recommended to do this in the last third of the night, so before Fajr prayers.
But recently with the summers timings her in UK it has become really difficult, as the isha prayer time starts at around 11:15 and the Fajr time starts at around 2:30, and this gap will further decrease as summer arrives.
I have found it very difficult to sleep for an hour after a full day of work and then wake up for tahajjud.
During such conditions can one pray tahajjud with isha? or not sleep at all and pray till fajr and then sleep?
Some guidance on this would really be appreciated.