Suppliers of household chemicals that could be used to make a terrorist bomb face up to two years in jail if they fail to check they are being used for legitimate purposes.

Priti Patel, the Home Secretary, on Thursday announced a crackdown on the sale and use of precursor chemicals in the wake of the Liverpool and Manchester terror attacks in which the perpetrators built home-made bombs.

Under proposed amendments to the Poisons Act, suppliers will be required to “verify the status and intended use” of any regulated chemicals that they sell such as hydrogen peroxide and nitric acid, key precursor components of terrorists’ bombs.

Suppliers are already required through the Act to report any suspicious activity to police, but the proposed changes increase their liability.

“The supplier would need to assess whether the intended use is consistent with the trade, business or profession. Where there is doubt or uncertainty, the sale could be refused and reported as a suspicious transaction,” said the Home Office consultation.

Ebay will have new legal duty

Company bosses and workers using the chemicals will also be placed under a legal duty to provide proof of their business and details of intended use to their supplier at regular intervals. “This is so the supplier can verify their status, record the details and assess suspicion,” said the consultation.

Online marketplaces such as Ebay will also have a new legal duty to report suspicious transactions and will be expected to set up systems so that they can.

“Reports would need to be made within 24 hours of considering that a transaction or attempted transaction is suspicious,” said the consultation.

They will also be expected to help their users “understand and comply with obligations” to verify sales and report suspicious transactions.

Ms Patel is also proposing to limit the concentrations of some chemicals sold to the public including hydrogen peroxide and nitric acid to make it harder for terrorists to get enough material to make a bomb.

More chemicals will be added to the list of those that fall within the regulations, requiring suppliers to carry out checks on sale and use.