UPDATE 7: Rockstar has said the GTA Online patch is live for PS3. It's working to have it released for Xbox 360 "as soon as possible today".

Here's the latest list of updates:

For PlayStation 3 users, a PlayStation Network server issue was detected that was limiting the amount of possible concurrent users. This was preventing most players from accessing GTA Online altogether and as of this morning, that problem was resolved.

There is an issue that is preventing some players from getting through the first tutorial mission across both platforms. Many players have been able to get through this with repeated retries, and we are working on unblocking this for everyone as soon as possible.

This morning, we experienced some instability across the GTA Online services which is affecting even people who have progressed beyond the tutorial mission. We are identifying these issues now and are working to restore stability for users as soon as possible.

For the time being and until we have been able to get everybody access to GTA Online and things are running smoothly, we have disabled the option of purchasable GTA$ cash packs. Players can however keep on earning GTA$ by pulling off Jobs and other profitable gameplay activities rather than purchasing cash packs.

UPDATE 6: Rockstar hopes to release a new patch for GTA Online today.

In an update issued last night Rockstar said: "We're currently working on a title update for both PlayStation 3 and Xbox 360 to address commonly reported issues with GTA Online. We hope to have it out for download as soon as tomorrow.

UPDATE 5: Technical issues with Grand Theft Auto Online are climbing at an alarming rate and Rockstar has decided to temporarily remove the option for micro-transactions until more errors are resolved.

"For the time being and until we have been able to get everybody access to GTA Online and things are running smoothly, we have disabled the option of purchasable GTA$ cash packs," Rockstar noted in a recent status update. "Players can however keep on earning GTA$ by pulling off jobs and other profitable gameplay activities rather than purchasing cash packs."

On the plus side, Rockstar solved an issue with PSN servers limiting the number of concurrent users, so it's slowly, but surely making progress on this troubled online game launch.

Current issues Rockstar is looking into include:

General network/cloud server issues

"Rockstar Cloud Servers Unavailable" error message

"Failed to Host a GTA Online Session" error messages

Errors saying "Timed out when matchmaking for a compatible GTA Online Session to join"

Errors about jobs failing to start or load

Misc. network and server-related error messages, disconnections, or cloud server errors

Errors saying "Mission Failed" as soon as the mission begins during a session

Long matchmaking load screens, eventually timing out after 10-15 minutes

Offline (disc-based) and online content mixing on the Jobs list

Ending up in a free-roam session with no jobs/markers on the map while playing as a temporary character during a cloud outage

Issues getting past the first Tutorial Race

Freezing while loading into first race in GTAO with "waiting for other players" on the screen

Seeing the same cut-scene twice in a row and then getting stuck on a load screen

Getting stuck transitioning into the lobby or race while other players are joining/leaving

Race Corona (start area, marker) not showing up for first race

Social Club Issues

General issues with the Social Club site and Social Club features (slow loading, failed logins, emails not arriving, etc). For more information on Social Club status, please see: http://support.rockstargames.com/hc/en-us/articles/200357093

UPDATE 4: A day after the launch of Grand Theft Auto Online and Rockstar is still battling a list of issues with GTA5's multiplayer mode.

The developer's checklist of problems has actually lengthened since yesterday - full details of which lie below.

"We are continuing to look into these issues and are working around the clock on resolving them as quickly as possible," Rockstar explained in an updated posted at 6am UK time this morning. "This includes close monitoring of our Support systems, forums, social media, and in-game data to measure traffic along with Community sentiment to ensure ongoing improvements to stability. Please stay tuned for more updates."

The developer is now aware of the following problems:

Occasional "Rockstar Cloud Servers Unavailable" error message

Freezing sometimes while loading into first race in GTAO with "waiting for other players" on the screen

Intermittent "Failed to Host a GTA Online Session" error messages

Race Corona (start area, marker) occasionally not showing up for first race

Errors saying "Timed out when matchmaking for a compatible GTA Online Session to join"

Occasional errors about jobs failing to start or load

General issues with the Social Club site and Social Club features (slow loading, failed logins, emails not arriving, etc). For more information on Social Club status, please see: http://support.rockstargames.com/hc/en-us/articles/200357093

Misc. network and server-related error messages, disconnections, or cloud server errors

Errors saying "Mission Failed" as soon as the mission begins during a session

Remain calm.

UPDATE 3: As expected, Rockstar's servers are buckling under pressure as millions attempt to play GTA Online.

Reports are flooding in from gamers who are unable to play, having downloaded the title update on both PlayStation 3 and Xbox 360.

Rockstar last week warned GTA 5 owners the Online game would experience issues, and so it has proved.

Now, it's said it's looking into the issue. These are the areas it's investigating:

Occasional "Rockstar Cloud Servers Unavailable" error message.

Freezing sometimes while loading into first race in GTAO with "waiting for other players" on the screen.

Intermittent "Failed to Host a GTA Online Session" error messages.

Rockstar Support has opened a page on its website to keep players in the loop.

UPDATE 2: GTA Online should be live now on PS3, Sony Computer Entertainment Europe has said.

Sign in to PlayStation Network, then load up GTA 5 and it will auto-prompt for the software update, which on PS3 is 39MB.

"Demand is high!" Sony tweeted.

UPDATE 1: GTA Online is available now on Xbox 360.

Eurogamer YouTube Editor Ian Higton was able to download the 59MB title update from Xbox Live, and is playing GTA Online now.

Keep calm and carry on.

ORIGINAL STORY: GTA Online will be available today from 12pm UK time, Rockstar has said.

It should, anyway - Rockstar last week warned it expects teething problems when the service launches, and has been frantically buying extra servers to cope with today's release.

This is how is should work, anyway. Today a small downloadable title update will be released on PlayStation Network and Xbox Live. Once installed, you get direct access to begin GTA Online, which will be unlocked in the GTA 5 game menu.

You can jump into GTA Online via the fourth (bottom) slot in your GTA 5 character wheel. But remember: the 12pm launch time frame is dependent on both title updates becoming available on each console's network, Rockstar said.

In a post on Rockstar Newswire, the company went into more detail on how GTA Online works.

It's set a few months prior to the events of GTA 5's single-player story. To prevent griefing, Rockstar has designed house party invitations specifically to be a friendly social affair where players can visit each other's houses without fear of having them ruined or losing their vehicles.

"If someone invites you into their property, then it is considered a friendly visit and you will not be able to shoot up their place or steal their cars from their garage," Rockstar said.

"By the way, in any given lobby, if you and another player own the same piece of property, you will each be able to enter your own personal instance of that property at any given time," Rockstar continued. "You will also be able to enter each other's instance of that property if you exchange and accept an invite. This way, multiple instances of ownership of the same property within a lobby can co-exist."

Rockstar then, again, addressed the thorny issue of GTA Online micro-transactions, which Eurogamer revealed last week.

"To allay some concerns we've heard on this subject, we can assure you that the game is designed such that the option of purchasable GTA$ should not disrupt the playing field - and there are a few mechanics in place to help ensure that," Rockstar explained.

"All players still have to rank up with Reputation Points (RP) in order to get access to purchase high-end items. No one can begin GTA Online and simply spend a lot of money out of the gate to get a leg up. You will have to earn your stripes and play to unlock access to the aspirational clothes, guns and other items.

"Please also remember that in GTA Online, hustling to afford the finer things by earning GTA$ doing robberies, stick-ups, winning races and other profitable activities is a fun gameplay experience rather than ever being a 'grind'."

Rockstar also pledged to tweak all areas of the game to make I fairer and iron out any balancing problems.