The new rates take effect from 8 December, and apply to both contract and pre-pay customers, according to Virgin.
An enhanced mobile web portal bearing the Virgin Media brand will be unveiled at the same time, offering news, music, video, games and entertainment content.
"By providing unlimited access at a highly competitive rate, we are giving all our customers the opportunity to use the internet on their phone without having to worry about racking up huge bills or working out complicated price structures," said Virgin Mobile managing director Graeme Oxby in a statement.
However, while the 30p per day rate is billed as offering unlimited access, a daily fair use policy of 25MB applies. Customers exceeding this will be charged £2 for each extra megabyte. Other network operators have similar fair usage policies.
Virgin Mobile said that it has confirmed more than 150 partners to provide content for the mobile portal, including Sony BMG, Sony Pictures, Disney, Hallmark, Universal, EMI, Warner Music Group, Glu and EA.
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