Welcome to coverage of opening practice for thr Monaco Grand Prix.

Perez immediately tops the timesheet with 1:25.280, after Karthikeyan improved to 1:27.755.

Karthikeyan's time now 1:28.772. Sauber's Sergio Perez comes out to join the 'fray'.

Hamilton says he has pushed his McLaren mechanics for improvements harder than anyone ahead of Monaco.

And now he goes round in 1:29.490 - not taking too many risks.

Still no sign of any other drivers. The latest improvment from the Indian is 1:30.435.

Still the only car out on track, Karthikeyan again lowers his mark to 1:32.260.

Karthikeyan improves by over three seconds to 1:35.367.

Narain Karthikeyan sets the first timed lap in the Hispania, 1:38.718.

Hamilton has also come back in. There are plenty of dolly birds around Monaco, as you might expect, with these competitors of the Miss Monaco GP beauty contest chief among them.

Button and Hamilton are out again, but 2009 champ Button returns to the garage after a brief run.

Facts, figures and track information ahead of the race.

Paul di Resta chats with his manager Anthony Hamilton as we await further action.

The drivers admit the Monaco GP will be a wide open race due to the uncertainty about the strategies for the event.

Ricciardo was fastest in Formula Renault 3.5 practice this morning. There is some difference between those cars and these...

The Mercedes duo of Michael Schumacher and Nico Rosberg have been out and come back in as this street circuit falls silent.

The McLarens are running a lot of updates this weekend.

Installation runs for former world champions Jenson Button and Lewis Hamilton, of McLaren, as well as Vettel's Red Bull team-mate Mark Webber.

Heikki Kovalainen is the first man out, followed by Jerome d'Ambrosio, Jarno Trulli and Vitaly Petrov. Ricciardo and world champion Sebastian Vettel are among the next cars to emerge.

The 90-minute session underway. Jaime Alguersuari will not run in this session, with Daniel Ricciardo taking the Toro Rosso spot.

Conditions are dry and sunny this morning and the forecast is for this to continue. Air temperature is 24 degrees.