Health warnings covering 65% of cigarette packs are to be introduced and menthol cigarettes banned under new EU rules approved today.
The European Parliament in Strasbourg voted on a raft of measures to help curb smoking but stopped short of introducing plain packaging for cigarettes and tobacco.
Legislators put new limits on advertising for electronic cigarettes but have so far rejected proposals for them to be regarded as medicinal products.
Menthol and other flavours will be banned but there is to be no ban on packs of slim cigarettes.
Some campaigners had called for e-cigarettes to be subjected to the same regulation as nicotine replacement therapies (NRT) such as patches and gum.
E-cigarettes consist of a battery, a cartridge containing nicotine, a solution of propylene glycol or glycerine mixed with water, and an atomiser to turn the solution into a vapour.
While nicotine is the addictive substance that keeps smokers hooked, Cancer Research UK said it is the toxic cocktail of chemicals in tobacco smoke that kills half of all long-term smokers.
The lack of tobacco in e-cigarettes means they are "almost certainly" a much safer way of getting a nicotine hit than smoking cigarettes, it added.
Liberal Democrat MEP Chris Davies said after the vote: "E-cigs can be a game- changer in the fight against smoking. Hundreds of former smokers have written to tell me that they have helped them give up cigarettes when nothing else worked.
"They are successful because they are not medicines but products that smokers enjoy using as an alternative to cigarettes.
"Every year 700,000 people in Europe die of smoking-related disease. We should not do anything that makes e-cigs harder to obtain than tobacco cigarettes."
Adrian Everett, chief executive of e-cigarette brand E-Lites, said: "This is a fantastic result for public health and the millions of smokers around Europe who are switching to e-cigarettes.
"We would have been in the absurd position of the Department of Health making it much easier to make and sell tobacco cigarettes than e-cigarettes which are vastly less harmful.
"Following the European Parliament's decision, we hope to work with the UK Government to agree a regulatory framework for e-cigarettes which reinforces the existing consumer protection regulations."
Conservative MEP Martin Callanan said: " Forcing e-cigs off the shelves would have been totally crazy.
"These are products that have helped countless people stop smoking more harmful cigarettes and yet some MEPs wanted to make them harder to manufacture than ordinary tobacco.
"I have received countless emails and calls from 'vapers' which were individual personal pleas, not a standard letter copied and pasted from an NGO website as we MEPs often see.
"Many electronic cigarettes are produced by small businesses who would simply not have been able to afford the strict authorisation demands the EU would place on them.
"We could not stand by and allow MEPs to put companies out of business and people out of work."
Tom Rolfe, president of the Skycig brand of e-cigarettes said: "Skycig welcome any regulations which will help us to ensure that under-18s cannot access electronic cigarettes and to ensure that all e-cigarette companies must produce products of a high standard, in the same way that Skycig and other reputable e-cigarette companies do."
Today marked the European Parliament's first reading of a draft tobacco directive which could become law in 2014.
MEPs voted to put health warnings on 65% of each cigarette pack, as opposed to the proposed 75%.
At present, warnings should cover at least 30% of the front and 40% of the back of cigarette packs, with a border surrounding them.
The Medicines and Healthcare products Regulatory Agency (MHRA) has said it intends to make e-cigarettes medicinal products but today's decision could alter those plans.
An MHRA spokesman said: "The UK Government's position is that the public health priority of reducing the harms of smoking can best be achieved by the regulation of nicotine containing products (NCPs), including electronic cigarettes, under the medicines framework and supports the European Commission's Tobacco Products Directive."
Once agreed, all 28 EU countries will have to make the measures law.