Dubai to London is just under 3,000 nautical miles, which puts it beyond every midsize aircraft and makes it a heavy-jet or ultra-long-range leg. Expect around seven hours in the air non-stop. Anything smaller would need a fuel stop, and no broker worth using would quote you one for this route.
Private jet charter from Dubai to London starts from $67,500 on the smallest suitable aircraft. That is an indicative starting price, not a quote: the figure for your trip depends on which aircraft are available, where they are positioned and the date you fly.