The details of 198 million Americans were left exposed on the internet by a data analytics firm that worked on the Republican campaign of Donald Trump, it emerged last night.

In the voter database used by the Republican National Committee in the 2016 election campaign were names, dates of birth, home addresses, phone numbers, and voter registration details, as well as information relating to probable ethnicity and religious affiliation.

It also included predictions of how individual voters felt on issues such as gun ownership, abortion, and stem cell research.

A file last updated in January included modeled data on individual voters most likely feelings on 46 separate questions including Mr Trump's "America First" foreign policy, and how important they would believe the US car manufacturing industry to be.

Deep Root Analytics, the contractor used by the Republican National Committee, said in a statement: "We take full responsibility for this situation.

" The data was equivalent to 10 billion pages of text and was in an Amazon cloud account that could be accessed without a secure log in.