THE SNP demanded the government sort out “unacceptable standards” at the Royal Mail on Monday.

The party called on regulator Ofcom to investigate the “appalling” service in the Highlands and Islands after the postal service issued three late delivery warnings in two weeks.

Royal Mail cited “local issues such as high levels of sick absence, resourcing, or other local factors” in three alerts starting on July 22.

New research shows that the Royal Mail has met its target to ensure 93 per cent of first-class deliveries are made within one day just three times — and not since 2016-17 — since privatisation.

In the most recent year, the service was only hitting 75 per cent of first class deliveries within one day.

This fell to 54 per cent in the Outer Hebrides, Orkney & Caithness, 61 per cent for Argyll and many Western Isles and a shocking 31 per cent in the Shetland Isles.

The average of the majority of postcodes in south London meanwhile hit at least 75 per cent with many in the 80s, the SNP-commissioned Scottish Parliament research showed.

SNP MSP Jenni Minto said: “The decision to sell off the Royal Mail by Westminster was short-sighted and neglectful. It is no surprise it’s been over a decade since they last met their targets.”

A government spokesman said: “Ministers have been clear with Royal Mail that services haven’t met the expectations of customers for quite some time now. It is particularly important that their service to rural and island communities improves. 

“We expect Ofcom, as the independent regulator of postal services, will take an active interest in their performance across the country.”