That's an old 350w fsp mate & a fairly decent one in all honesty .
It'll manage a 1050ti fine.
& honestly spend the extra £5 or so on the 1050ti , its 30-40% stronger than the 1050 you listed from Curry's.
Do you know the rest of your system specs?
Bear 2 extra things in mind
1. These cards have no analog output - they won't work on a VGA only monitor without spending an extra £10-15 on an active digital to VGA converter.
If your monitor has dvi or HDMI you're fine.
2. If you're running a Dell or HP prebuild (that psu makes me think you may be) some of the motherboard have sketchy or no support for these new cards.
If I'm right then run CPU-z ,
http://www.cpuid.com/softwares/cpu-z.html
open the motherboard tab & either take a screen grab & upload again to post image or just copy & paste the motherboard model & BIOS revision here