Alejandro Agag prepared to cancel Formula E's Moscow event

The championship has written permission from Russian president Vladimir Putin and the security services of the Kremlin, which the circuit is adjacent to.

But the city authority is yet to confirm it will close the roads needed for the circuit.

Agag told Autosport the issue was "totally on their side".

"I haven't got the green light yet. I haven't got the red light - I have an orange light, which isn't any good," he said.

"We're ready. We have everybody with their visas, all the finance, everything.

"But we don't have the permission from the city to close the traffic.

"It hasn't given the red light but I can't do a race with an orange light.

"I don't think it's correct what their doing so I'm really putting pressure to get the final answer and if I don't I'll call it off."

The series overcame issues last year to hold the inaugural Moscow ePrix and Agag initially set a May 15 cut-off date for the government if this season's race is to go ahead, but Autosport understands a decision is now expected this week.

If Moscow is dropped, the calendar is almost certain to be reduced to 10 events, leaving just the Berlin race on May 21 and London's July 2-3 double-header.

Championship rivals Lucas di Grassi and Sebastien Buemi both played down the significance of the potential cancellation.

"It's so close that it doesn't really matter," said championship leader di Grassi.

"I don't think it makes a huge difference if one race is dropped or not.

"I would like to do it but I don't think it changes much."

Renault e.dams driver Buemi trails di Grassi by 11 points in the standings.

He added: "It's always good to have more races.

"It would be a shame to lose Moscow, but we'll take it as it comes - if we go there we'll try to win and if not we'll focus on London."