ISPs will be barred from blocking or throttling customers' access to services that rival their own under new net neutrality rules that could soon be enforced across Europe.

The European Commission said that around 100 million Europeans face restrictions on their internet services because ISPs are reluctant give customers access to services which compete with their own offerings.

Plans to mandate net neutrality now being put forward by the EC's digital chief, Commission vice president Neelie Kroes, would prevent anti-competitive blocking of rival services.

Currently only the Netherlands and Slovenia have net neutrality guarantees but Kroes said she wants similar rights for the rest of Europe.

Net neutrality is an issue that Europe has been discussing for a number of years, with momentum gradually moving towards making it a standard across Europe.

Kroes said that some services such as Skype and WhatsApp are being deliberately degraded or blocked outright by some ISP "simply to avoid the competition".

"In my view, such ideas are on their way out. Most consumers see the richness and vibrancy of the full, unlimited internet and wouldn't want anything less," she said

Speaking in Brussels today, she added: "Equally, it's clear to me that many Europeans expect protection against such commercial tactics. And that is exactly the EU safeguard we will be providing. A safeguard for every European, on every device, on every network: a guarantee of access to the full and open internet, without any blocking or throttling of competing services."

A 2011 study by European regulators found that services are blocked or degraded, often without their knowledge, for around one in five fixed lines, and for more than one in three mobile users.

Kroes said this hurts consumers – because they don't get the service they paid for, and start-ups "because they lack certainty about whether their new bright ideas will get a fair chance to compete in the market".

Kroes acknowledged that ISPs have legitimate reasons to manage how internet traffic flows through their networks, for example to avoid congestion and so ensure quality, or to weed out spam, which she said was "something which has made a real positive difference, which I'd say most users find helpful, and are happy with".

Similarly, different users have different network needs — from merely sending a few emails to constantly watching video — and thus ISPs should be allowed to offer different internet access packages.

Kroes also said there should be more transparency, particularly in consumer broadband contracts, so people can understand what they are really buying. "We all deserve a clear promise before signing up — not a nasty surprise after. After all, when you buy a carton of milk, you don't expect it to be half-empty: the same goes for 50Mbps internet."

The next step is to work out whether the net neutrality plans should be put forward as a 'legal recommendation' or a 'regulation'.

If net neutrality is taken forward as a recommendation, it could be in place by December this year, while if it is made into a tougher regulation, it will take until Easter 2014 to pass both the European Parliament and European Council, and even then won't actually be law in each of the EU member states until 2015.