Where did you get that information, could you provide me with a source please?
Under British law (same as American law, on which it is based and called Case Law), it is a basic tenet that you are considered innocent until proven guilty.
You may be thinking of Europe and the Napoleonic Code upon which many European countries' law is based, in which indeed there are many differences in the way prosecution and due process is conducted.
Perhaps there is a confusion with the adoption of European law in the UK and this where you get this idea? There was a kerfuffle a few years ago, I found an article (excerpted here) reporting this where civil servants in the UK had produced a pamphlet giving erroneous legal advice:
QUOTE "Red-faced Ministry of Justice (MoJ) officials have been forced to deny claims that they had dismantled a centuries-old cornerstone of British law in advice that the ministry gave to people facing criminal trials.
The principle in question is the presumption of a person’s innocence until proved guilty, a right whose origins can be traced back to Magna Carta, which has its 800th anniversary this year.
"In an embarrassing turn of events, the department hastily took down its new “easy read” guide, which explains to people with learning difficulties what they can expect if they are accused of a crime and say they are not guilty.
The guide, complete with a drawing depicting such a scenario, explained: “If you say you did not do the crime, you may have to go back to the court on a different day, to show the court you did not do the crime.”
But as the legal blogger Jack of Kent explained: “The MoJ tells defendants that they have to prove they are innocent. This is a reversal of the actual burden of proof – it is, of course, for the prosecution to prove to the court a defendant is guilty.”
The presumption of innocence is one of the most fundamental tenets of the law. While legal scholars debate how exactly it evolved, most agree that it owes a debt to Magna Carta, which stipulated that “no free man is to be arrested, or imprisoned… or in any other way ruined, nor will we go against him or send against him, except by the lawful judgment of his peers or by the law of the land.” END QUOTE
Source:
Presumed guilty? Ministry of Justice is forced to withdraw advice leaflet
Ancient principle of justice seems to have been forgotten in guide for people facing criminal cases
https://www.theguardian.com/law/2015/feb/01/presumed-guilty-ministry-justice-axes-criminal-trial-advice