Until now, Google’s social network – which aims to beat Facebook to the top – has made users get an invite from existing users or Google employees before they join.

But now the site, which launched in June, has announced that anyone will be able to sign up.

The social networking site has already reached over 25 million members – a figure which is expected to grow to 100 million by the end of the year.

It took Facebook 10 months to reach 1 million members after they launched in 2004.

Vic Gundotra, senior vice president of engineering at Google, wrote on the company blog: “For the past 12 weeks we’ve been in field trial, and during that time we’ve listened and learned a great deal.

“We’re nowhere near done, but with the improvements we’ve made so far we’re ready to move from field trial to beta, and introduce our 100th feature: open signups.”

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?Google made the announcement yesterday – just two days before Facebook’s annual conference, f8.

At the conference, Facebook is expected to launch a new digital music service and media platform with several content partners.

Google+ has also made some changes to the site as it opens up to the public, including a new video “hangouts” feature, where people can talk in groups through video on Android-powered phones. “Hangouts” can also be broadcast publicly.

Users can also search for content without leaving the social network site.

All three main party leaders, David Cameron, Nick Clegg and Ed Milliband opened Google+ accounts last week.