Large companies should help support smaller firms by paying them promptly, a business leader has urged.
The Government should also do more, by reforming business rates and improving access to finance, said the Federation of Small Businesses (FSB).
Policy chairman Mike Cherry said supporting small firms should not be a "nice to have" afterthought to policymaking.
Speaking ahead of the FSB's policy conference in London, he said: "The Government must focus on how they can support these businesses in job creation and growth while the UK's large businesses need to play their part too in supporting ambitious small businesses, for example through paying their smaller suppliers promptly."
The FSB has described business support as "congested and confusing", saying the system in the United States should become a model for the UK.
Research shows hundreds of support schemes to help small firms, yet with little take-up or effect. The FSB believes the current situation is too complex for most businesses to understand, and has looked to the US for comparison.
Karen Mills, ex-head of the United States' Small Business Administration and a former member of President Barack Obama's cabinet, will address today's conference.
She said: "As governments look to the future, their plans have to be centred on growth, and the primary currency should be well-paying jobs. With that, any conversation focused on jobs must include small business and entrepreneurship.
"When small business has a seat at the table, we can more effectively focus on entrepreneurship and innovation, which are critical components to a strong economic game plan in today's world."
A spokesperson for the Business Department said: "The Government has already taken a number of actions to help small businesses - including encouraging more businesses to sign up to the Prompt Payment Code and ensuring the public sector leads by example.
"We published our small business strategy last month to build on this, and are looking at what more we can do to tackle late payment. We have also established the British Business Bank to address access to finance issues.
"The Government is working hard to ensure Britain is the best place to start and grow a business, and from April all businesses will benefit from a £2,000 cut in their National Insurance bill."