The Met Police already own 350 stun guns
Stun guns will not be given to all frontline officers as they could "cause fear and damage public confidence", the Metropolitan Police Authority has said.
Comments from the Metropolitan Police's (Met) watchdog came after Home Secretary Jacqui Smith called for the use of Tasers to be extended.
The Met's specialist firearms officers and specially trained officers from the territorial support group use the guns.
Extending their use may be perceived as "indiscriminate" the watchdog said.
Taser stun guns release a 50,000-volt charge which can temporarily disable suspects.
The Met said it owned 350 stun guns and not all of them were deployed to officers.
A statement from the Metropolitan Police Authority (MPA) said it had "no intention of immediately sanctioning any increase in the availability of Tasers to officers in the Met".
"The MPA recognises the potential to cause fear and damage public confidence if the use of Tasers is extended to non-specialist trained police officers and is perceived by the public to be indiscriminate.
"Both the MPA and the MPS will pause to take stock before deciding whether to take advantage of the extra funding."
Although in many cases Taser guns have proved "very effective", "their use must be tightly controlled and we have seen no case made out to extend their availability", it added.
The MPA said the decision to extend their use to the Met's territorial support group was taken after "extensive consultation".
On Monday Ms Smith said the government planned to spend £8m to buy 10,000 more Taser guns for frontline officers.
Commander Bob Broadhurst said the guns would be used in incidents "involving violence or threats of violence with such severity that officers would need to use force to protect the public, the subject themselves and their colleagues".