Brexit uncertainty and a global slowdown will likely limit the United Kingdom's economic growth to a paltry 1.3 percent in 2019, according to the forecasting group EY Item Club.

The prediction in the group's latest report was revised down from the 1.5 percent it anticipated previously.

UK-based EY Item Club, which has been producing widely-quoted quarterly economic forecasts since 1977, said the UK started 2019 with relatively robust growth, but that it was artificially high because of an unprecedented increase in stockpiling by companies bracing for a disruptive no-deal Brexit. The forecasters said the start to the year was effectively a "false dawn".

Howard Archer, EY Item Club's chief economic adviser, said: "Delays to Brexit, a difficult domestic economic and political backdrop, and slower global economic activity have resulted in a weaker outlook for UK GDP growth this year."

The forecaster said the first three months of 2019 were "almost certainly boosted by stockpiling in the manufacturing sector, and to a lesser extent by consumers".

The report explained that companies bought more components and raw materials in the approach to the March date by which Brexit was scheduled to happen, amid concerns that a disruptive "no-deal" exit from the European Union was looming. But, with the UK's pending exit now pushed back to Oct 31, and a no-deal Brexit effectively off the table, the stockpiles are less important and will likely be run down, meaning economic growth could be weaker.

Archer said a lack of Brexit clarity will have other impacts on the economy.

"Prolonged uncertainty is likely to impact on businesses' willingness to invest and commit to any new major projects," he said.

EY Item Club predicts Brexit will negatively impact the UK economy throughout 2019, something that will effectively block the Bank of England from raising interest rates.

The national bank is scheduled to publish its decision on Thursday on whether it will adjust interest rates. It will also release its quarterly inflation report and Mark Carney, the bank's governor, will describe the health of the UK economy.

Carney has been vocal recently on the need for banks to address global warming because of the threat it poses to economies and campaign groups, including Positive Money and Fossil Free London, have said they will stage protests outside the Bank of England that day to urge Carney to continue to address the issue. The Guardian newspaper said they will unveil banners calling on Carney to "put your money where your mouth is" and "unleash green investment now".

The EY Item Club's latest report is broadly in line with one published last month by the Office for Budget Responsibility that said GDP was likely to grow by 1.2 percent in 2019.