The advertisement will be shown on Channel 4 in May and June
An advertisement by an abortion advisory organisation is to be screened for the first time on UK television.
The campaign for unplanned pregnancy and abortion advice at Marie Stopes clinics will raise awareness of sexual health, the organisation said.
The 30-second film to be shown on Channel 4 will first air at 2210 BST on 24 May and run until the end of June.
Anti-abortion groups said the charity's move trivialised human life and a legal appeal was being considered.
The advertisement does not mention the word abortion but asks "Are you late?" and points those facing an unplanned pregnancy to Marie Stopes International's 24-hour helpline.
Marie Stopes, which is run on a not-for-profit basis, says callers will be given "non-judgemental support, advice and services".
The Advertising Standards Authority (ASA) said non-commercial providers of post-conception advice services had long been permitted to run advertisements.
In a statement, Marie Stopes said: "In the past it was unclear whether unplanned pregnancy advisory services could advertise on TV... Following a consultation we have found that it is allowed under the current guidance because we are a charity and not a commercial organisation."
The latest official figures for 2008 show that there were 195,300 abortions in England and Wales and 13,817 in Scotland.
Marie Stopes said about 80% of the abortions it provided in 2009 were carried out for free on the NHS.
Marie Stopes chief executive Dana Hovig said: "Last year alone we received 350,000 calls to our 24-hour helpline. Clearly there are hundreds of thousands of women who want and need sexual health information and advice and access to services.
"We hope the new Are you late? campaign will encourage people to talk about their choices, including abortion, more openly and honestly, and empower women to reach confident, informed decisions about their sexual health."
Michaela Aston, a spokeswoman for anti-abortion charity Life, said: "To allow abortion providers to advertise on TV, as though they were no different from car companies or detergent manufacturers, is grotesque.
"By suggesting that abortion is yet another consumer choice, it trivialises human life and completely contravenes the spirit of the 1967 Abortion Act, which was supposed to allow for a small number of legal abortions in a limited number of hard cases, but has been twisted and distorted to allow for mass abortion on demand."
The Society for the Protection of Unborn Children said it was taking advice on the legality of the advertisement.
It called on the culture secretary to make regulator Ofcom impose restrictions on such broadcasts.
Spokesman Anthony Ozimic said Marie Stopes' "huge multi-national revenue means it can afford TV advertising, which is hugely expensive. This creates an unfair playing field, as pro-life groups simply cannot afford any such advertising".
He added: "Abortion ads will trivialise abortion. It is an insult to the hundreds of women hurt by abortion every day. Such ads are offensive and will mislead viewers about the reality of abortion."
The first advert for Marie Stopes will be shown during the Million Pound Drop Live game show hosted by Davina McCall.
An ASA spokesman said: "Any ad that airs has to comply with all the relevant rules in the Advertising Code, which aims to ensure that ads are not misleading and socially responsible.
"Ads must adhere to rules that are designed to protect children and vulnerable groups and prevent ads from causing serious or widespread offence. TV ads are checked against the rules before they are broadcast.
"If viewers have concerns about the content or scheduling of the ad, the ASA is able to consider complaints once the ad has aired."