An Algarve estate agent today posted a copy of an e-mail received from a prospective buyer in which a viewing booked for next month has been cancelled.

“Please could I cancel these viewings”, the email reads, adding: “This is due to the EU referendum (Brexit) result. Apologies for any inconvenience.”

An international school was also told on Friday morning that the enrolment of two British children would be put on hold due to the outcome of the referendum, with the prospective parent continuing to say that he was heading off to his lawyers to cancel the purchase of a property.

Portuguese business people in the UK have also expressed worry over how Brexit is going to affect them.

José Cruz, who runs one of the biggest importers of Portuguese products into the UK told the Lusa News Agency that "we are going to struggle and we need to make immediate decisions."

The director of Atlântico added that his company does not only deal with Portugal, but with other countries who trade in the dollar.

"We are going to have to increase our prices, we are not sitting around waiting for better news", he said.

Guilherme Rosa, elected for Labour in Stockwell, south London, and where there is a large Portuguese community, said that it was going to be "economic doom here."

He added that talk in Stockwell is also about how holidays will become more expensive and they "won't be able to visit Portugal as often."

There were also concerns that the euro would devalue strongly against the dollar, meaning that with almost immediate effect, fuel prices here would rise as Portugal pays in dollars to obtain oil.

Sterling, which has devalued by ten percent against the euro since the beginning of the year, would also result in holiday makers heading for Portugal this summer having less to spend, with fears growing that real estate purchases could also be negatively affected.

The Algarve Tourist Board and the the region's largest hotel association have as a result also expressed concerns over the outcome of Thursday's vote in comments to Lusa.

RTA chief Desidério Silva and AHETA chairman Elidérico Viegas, have both agreed that a weaker pound will have a negative effect on tourism from which is the region's biggest tourist market.

The Algarve tourism president added that the Algarve should now look to other markets, such as the German, French and Dutch to compensate an eventual drop in British tourists.

Desidério Silva adds that the loss in buying power will also be "a negative factor" for Britons living in the Algarve.

Elidérico Viegas meanwhile explained that his association is "concerned with this situation, the instability created around Brexit could have implications, most certainly for companies and the financial results of the region.

The pound is forecast to drop even further with the resignation of British Prime Minister David Cameron on Friday morning.

The Lisbon Stock Exchange had also hit a 20-year low by Friday afternoon, with fears now also that Portugal could struggle with its regular sales of sovereign debt as yields have already sky-rocketted on Friday and concerns are now that could approach rates that could prove unsustainable - the major reason behind Portugal calling for a bailout back in 2011.

The PSI-20 principal index fell close to 11% to 4.17 points in early Friday trading, its lowest level since January 1996, EFE news reported.

Shares in Banco Comercial Portugues (BCP) tumbled more than 17% to trade at just 1.7 euro cents per share.

Meanwhile, Portuguese working and living in the United Kingdom have on Friday also expressed concerns over the referendum result, saying that they “no longer feel welcome in Britain.”

“It is very worrying, as we don’t know what is going to happen to us. All we know as that they don’t want us here any longer”, a Portuguese Communities advisor in Wales told Lusa News Agency.

According to Iolanda Banu Viegas, Portuguese residents in Wales, where a large majority voted Leave, are “extremely concerned.”

Iolanda Viegas added she had been inundated with calls, but says she has been unable to address most of the questions being levelled at her by Portuguese emigrants.

Manuel Mendonça, founder of the Portuguese Association Heróis do Mar and who is based in Great Yarmouth in Norfolk, revealed that the Portuguese community is in a state of “shock.”

“People here are fearing for their futures”, he was quoted as telling Lusa News Agency, “we don’t feel welcome here as the Leave campaign focussed almost entirely on immigration. The economy here will fall and people will start thinking about leaving”, he said while forecasting a period of great instability.

He added that the anti-immigration sentiment has been concealed for some time in the region, where the Portuguese community has grown considerably in recent years due to large numbers of vacancies in the agriculture industry and food processing factories.

Manuel Mendonça also encouraged Portuguese workers to ensure their children are taught in their mother tongue as they might need to return to Portugal sooner than they had bargained for.