Britons have become increasingly pessimistic about the long-term effects of Brexit on the economy, according to the latest household finance index survey by IHS Markit.

Just days before the UK triggers Article 50 to formally set the Brexit process in motion, the research firm found even the older generation and the poorest households, who were initially the only segments of population to be optimistic about Brexit, have changed their minds.

The lowest income group, which includes households earning less than £15,000 a year, was the most optimistic shortly after the referendum, but it has now become the most pessimistic group.

Against Brexit: Pro-EU protesters gathered in Parliament Square last Saturday

Only 29 per cent of households saw Brexit having a positive long-term impact on the economy, down from 39 per cent last July shortly after the referendum.

Meanwhile, the proportion of households who saw the departure from the EU having a negative impact also worsened to 53 per cent from 42 per cent in July.

Chris Williamson, chief business economist at IHS Markit, said: 'Whereas opinions on the long-term impact of Brexit were finely balanced in the immediate aftermath of last June's vote, albeit leaning towards pessimism, a negative view of the economic consequences has become increasingly apparent and widespread.'

'Pessimism has now spread to all age groups and income brackets. Shortly after the referendum, the older generations and the very poorest families were the exceptions in considering Brexit to be beneficial to the long-term health of the economy. However, even these pockets of the population have now become pessimistic.'

Sentiment shift: Older generations have now become pessimistic about the impact of Brexit

The very poorest families, who were the most optimistic, have become the most pessimistic

The survey of 1,500 adults carried out last month also shows that those working in the public sector have become more negative than those employed in the private sector, having seen similar degrees of pessimism last July.

Only those working in manufacturing and construction were positive on balance about the long-term impact of Brexit, with the number of optimists in fact outnumbering pessimists in both sectors to a greater extent than seen last year, IHS Markit said.

The greatest degree of pessimism was again seen in media, culture and entertainment, followed by IT & Telecoms and education, health & social services.

Williamson added: 'Only those working in manufacturing and construction see Brexit as beneficial to the long-run health of the economy, the former presumably perceiving some benefit of the weaker pound in boosting exports.'

Official EU exit: Prime Minister Theresa May will trigger article 50 on Wednesday

He noted that much will depend on the Brexit negotiations, which are expected to begin in May or June, after Prime Minister Theresa May's trigger of the article 50 on Wednesday, which will effectively kickstart the UK's two-year formal exit process.

Sentiment has turned negative in all regions, with Scotland remaining the region with the highest level of pessimism about the long-term impact of Brexit, followed by the North East and London.

Even the North East, which was one of only four out of the 11 regions to be positive on balance shortly after the referendum, has now turned negative.

The survey comes as job site Indeed warned that EU workers' appetite for the UK jobs market was cooling 'dramatically'.

Since the start of 2017 the number of people in other EU countries searching online for UK jobs has slumped by 18 per cent, according to Indeed.

EU workers: The drop is the sharpest recorded since the UK voted for Brexit last June

The drop is the sharpest recorded since the UK voted for Brexit last June, and takes the number of inbound job searches to 11 per cent below its post-referendum trough.

Meanwhile traffic in the opposite direction is increasing, with the number of UK residents looking for work in other EU countries ticking up since the start of January.

Mariano Mamertino, EMEA economist at Indeed, said: 'As Article 50 looms, we are seeing a sharper and longer decline in interest in working in the UK than in previous 'shock drops' following last year's referendum. As Brexit moves from rhetoric to reality, the strain on Britain's strong but tight labour market will worsen.'

A separate Indeed analysis of official ONS data revealed that the UK is heavily reliant on EU workers, with one million jobs, or over 44 per cent of all new jobs created in Britain since 2008, filled by people born in another EU country.

The dependence is most acute in the manufacturing and hospitality sectors, which together account for a quarter of all EU nationals employed in the UK.

'Such heavy reliance on European talent could prove a serious liability if Brexit interrupts the flow of workers. With Europeans' appetite for working in the UK already on the wane, if a non-EU Britain puts up legal barriers to EU workers coming here, or if the UK economy slumps in the wake of Brexit, European jobseekers won't hesitate to look elsewhere,' Mamertino added.