Jo Swinson has insisted Liberal Democrat plans to abolish business rates will “rescue the High Street”.

Speaking at the CBI conference in London, Ms Swinson also said staying in the EU would deliver a £50 billion boost to the economy as she claimed the Liberal Democrats are now the “natural party of business”.

Ms Swinson pushed Lib Dem plans to replace business rates with a commercial landowner levy as “bold and innovative”.

She said: ”The Liberal Democrats are committed to supporting small businesses who are the engine of our economy.

“That’s why the Liberal Democrats would scarp business rates and replace them with a commercial landowner levy.

“It will shift the burden from the tenant to the landlord so that we can breathe new life into our high streets.”

Ms Swinson insisted the measure would “rescue” the High Street.

“This is an innovative and bold policy that is needed.

“Let’s remember what the issues are that we’re trying to solve here – businesses on the high street have been struggling for many years now and they find the business rates can be a crippling cost and this is at a time when they’re already having to deal with footfall falling, competition from online competitors where they aren’t having to pay the same type of rates.

“So, I think this is an important change, and clearly it being borne by landlords – some of that may well be passed on but we also recognise it will not all be – and this will provide a significant boost for businesses.”

Ms Swinson said remaining in the EU would deliver a £50 billion boon to the UK economy.

She said: “Boris Johnson talked of a Brexit boom this morning, but we know it is much more likely to be a Brexit bust.

“We believe that being part of one of the most successful economic blocs in the world is the best guarantee we can have for our future.

“For the success of our businesses and for our country, we believe that our best future is as members of the European Union.

“That’s why a Liberal Democrat government will stop Brexit on day one,” she said to applause from delegates.

Ms Swinson said without freedom of movement Labour and the Tories would struggle to fulfil their pledges.

She said: “Without the European bricklayers, engineers and builders, they won’t be able to build the homes, hospitals, schools and railways they’ve promised – we can’t build it unless they come.”

Ms Swinson called the Lib Dems the “natural party of business”, adding: “With the Conservatives in the pocket of Nigel Farage and Jeremy Corbyn stuck in the 1970s, we are the only ones standing up for you.”

She added that a Liberal Democrat government would introduce a “general duty of care” requiring businesses to consider their environmental impact.

The Lib Dem leader said: “We we will introduce a general duty of care for the environment and human rights for all companies and public sector agencies.”

Ms Swinson added: “And we will ask all UK listed companies and private companies with more than 250 staff to have at least one employee representative on their boards.

“That will help rebuild trust between workers and bosses.”

Shaun Connolly is PA Political Correspondent.