The UK government must act to fix Scotland's "unacceptable" mobile phone coverage, the Federation of Small Businesses (FSB) is set to tell MPs.
The FSB says official figures show 17% of Scotland's landmass has 4G mobile coverage, compared to 60% in England.
It will also tell Westminster's Scottish Affairs Committee that superfast broadband availability still lags behind the UK as a whole.
The UK government say coverage where people live and work is improving.
The Scottish Affairs Committee is currently investigating digital connectivity in Scotland.
The industry regulator Ofcom has produced figures showing indoor 4G coverage in Scotland sits at 53% in Scotland, while it is 58% across the UK and 60% in England.
It also says superfast broadband availability is 87% north of the border, but 91% UK-wide and 92% for customers in England.
Representatives of the FSB will tell the committee on Monday that Scotland-specific coverage obligations should be attached to future mobile spectrum sales.
Andy Willox, the FSB's Scottish policy convenor, said: "It doesn't matter if you're a corporate high-flyer, a local tradesperson or an international tourist, Scotland's spotty mobile connectivity results in missed opportunities and wasted time.
"While some allowances could be made for differences in geography and population density, these figures show that the gap between Scotland and England is unacceptably wide - as it has been for some time.
"Ofcom have suggested that nation-specific coverage obligations might be a means to address this embarrassing problem. The Scottish Affairs Committee must push the UK government to take up this proposal."
Mr Willox said the Scottish government, UK government and local government must work more closely together "to develop digital infrastructure that works for Scotland".
He said: "Improving Scotland's historically patchy digital infrastructure is a top priority for Scotland's business community. Therefore, politicians from across the political spectrum must work constructively to develop realistic plans which deliver for local economies and communities."
Easier and cheaper
A spokesman for the UK government's Department for Digital, Culture, Media and Sport said: "We recognise the geographical challenges of delivering improved mobile coverage in Scotland, however coverage where people live, work and travel is improving.
"But we know there is more to do which is why we reformed outdated laws, making it easier and cheaper to install and upgrade digital infrastructure."
A Scottish government spokesman said: "Despite powers being reserved, we have been using all the powers at our disposal to ensure that mobile coverage is improved in Scotland.
"Last year we announced the launch of the Scottish 4G Infill programme to deliver improved coverage. In developing this programme, we have acted upon learned lessons from the UK government's failed Mobile Infrastructure Project which delivered only three of a planned 84 sites in Scotland.
"We have also published our Mobile Action Plan, the first of its kind in the UK to bring together industry and government to improve mobile coverage."