The UK's chaotic withdrawal from Afghanistan last year showed "systemic failures of leadership, planning and preparation", according to a scathing inquiry by British MPs published on Tuesday.

The House of Commons Foreign Affairs Committee probe revealed a "fundamental lack of planning, grip or leadership at a time of national emergency" before and during the Islamic Emirate of Afghanistan (IEA) takeover of Kabul in August last year, France24 reported.

"The manner of our withdrawal from Afghanistan was a disaster and a betrayal of our allies that will damage the UK's interests for years to come," the report said.

At the time, Prime Minister Boris Johnson hailed a mission "unlike anything we have seen in our lifetimes" with the UK airlifting over 15,000 people in two weeks.

But foreign secretary at the time, Dominic Raab, was heavily criticised for not immediately leaving a beach holiday when the IEA took control.

The report however stated that during the run-up to the IEA takeover, the government and civil servants suffered from an "optimism bias" that the US would change its mind about withdrawing, despite it having been announced by president Donald Trump in February 2020.

"The UK government failed adequately to shape or respond to Washington's decision to withdraw, to predict the speed of the Taliban's (IEA) takeover, or to plan and prepare for the evacuation of our Afghan partners," it added.

"Most damning for the Foreign Office is the total absence of a plan for evacuating Afghans who supported the UK mission, without being directly employed by the UK government, despite knowing 18 months before the collapse of Afghanistan that an evacuation might be necessary."

In responding to questions from the Committee, which started work on the report in September, the Foreign Office "provided answers that were intentionally evasive and often deliberately misleading".

Instead, two whistleblowers provided crucial testimony to the committee, France24 reported.

"Those who lead the Foreign Office should be ashamed that civil servants of great integrity felt compelled to risk their careers to bring the situation to light," the report said.

The committee called on the government to "commit to a serious strategy for future engagement with Afghanistan", warning that "attempts to isolate the new regime entirely may only hurt the Afghan people and leave a vacuum to be filled by China.

"Failure to do so would abandon women and girls in the single biggest reversal of rights in a generation," it said.

It called on the UK to re-establish a diplomatic presence "as soon as it is safe to do so, and to work with those on the ground who can support civil society", France24 reported.