Would you care to enlighten us with what you see as untruths
Your claim, in the title and text of your post that Sadiq Khan is responsible.
This confected and incorrect furore appears to date back to an anonymous tweet, archived here archive.ph/4uCGk on June 23, which said
“This obnoxious little turd has banned taxi's from flying the England flag while the Euro's are on.
'It will distract motorists'.
What a lying bastard.
Not bothered about Palestinian flags flying around London or protesters stopping traffic.”
No evidence for this was offered, but this was still seized upon by the right wing press (and the muckraking Farage) as ‘fact’.
TfL responded, on June 24th, by email to fact checking organisations and media outlets who bothered to check (my bold in this, not theirs)
“ Decisions relating to the licensing and regulation of taxis and private hire vehicles in London are taken by TfL, not the Mayor.
For the safety of all passengers and drivers, there are guidelines in place about what can be displayed in or on taxis and private hire vehicles in London. These are longstanding guidelines that have been around for decades.
Only official signs and stickers can be displayed. Any other signage, which includes flags, is not permitted due to safety concerns. Many other licensing authorities across the country take a similar approach.
The rules apply to all signage, including flags, and are not specific to the St George's Cross or any other national flags."