The chaos that marred the opening day of Heathrow's flagship £4.3bn Terminal 5 continued yesterday as administrative problems failed to be resolved. More delays are expected today.

As nearly 80 flights to and from the London hub were cancelled yesterday, British Airways' embarrassed chief executive Willie Walsh accepted the debacle had affected the reputation of BA and of Britain and warned problems could persist this weekend.

As Scottish industry bodies launched a scathing attack last night on the disruption, claiming that Scotland had been disproportionately affected by the problems at T5, First Minister Alex Salmond joined in. He said that Scotland was getting "fed up".

He said: "Filtering everything through Heathrow leaves us extremely vulnerable. We need more direct flights and, of course, we should have a fast train service north to south."

Andy Willox, the Federation of Small Businesses' Scottish Policy Convener, said: "It is an open secret that flights to and from Scotland are the first to be scrapped in order to clear the backlog and handle more lucrative international flights."

Liz Cameron, chief executive of Scottish Chambers of Commerce, added: "It seems once again that services to and from Scotland are suffering disproportionately."

But BA said the industry bodies' claim was "absolute rubbish" and pointed out that out of the near 80 short-haul flights cancelled yesterday, only a handful were to or from Scottish destinations.

Around one-fifth of flights going in and out of Terminal 5 were scrapped yesterday, with short-haul worst affected, as it sought to recover from the mess left by Thursday's opening disaster when nearly 70 flights were cancelled. However, passengers could check in hand and hold luggage.

Six of the cancelled flights were to and from Scottish airports - Edinburgh (3), Aberdeen (2) and Glasgow (1).

Mr Walsh admitted the airline had "got things wrong" and said he expected there would be some cancellations today as the knock-on effect continued. He said he accepted full responsibility for the chaos but would not resign his post in the wake of the PR catastrophe for the carrier.

The transfer of operations from Terminal 4, which was due to take place on April 30, was now "under review", he said, following the troubles they had encountered.

The 44-year-old Irishman said lessons would be learned, some but not all of the teething troubles had been anticipated and he hoped the terminal, previously praised as a solution to Heathrow's chronic congestion, would be working 100% to schedule as soon as possible.

He said that if one of the numerous hold-ups - including staff car-parking problems, staff security screening and baggage delays - had happened "in isolation", then the resulting travel chaos would not have been so severe.

"Yesterday was definitely not British Airways' finest hour. We disappointed many people and I apologise sincerely. I take responsibility for what happened. The buck stops with me," he said.

"Our performance was not good enough. We did not deliver for our customers and we should have."

Mr Walsh said the situation was genuinely "a combination of problems". He said staff arriving found difficulties getting in and there were delays getting airside, putting them "under pressure from the very beginning". There was then a system failure when staff tried to log in, which was tracked back to "human error".

Airport operator BAA said it was working with BA to resolve baggage problems.

"At T5, we are focusing all our efforts on our work with BA to resolve baggage issues and to deliver a good service to passengers," said a BAA spokesman.

BA claimed "staff familiarisation" was partly to blame and staff have pointed the finger at lack of training and essential support.

More than 3.3 million people fly between Scotland and Heathrow every year, more than to any other destination. Just more than one in six people who board a plane in Scotland are Heathrow-bound.

Aberdeen MP Anne Begg, who uses a wheelchair, said she was boycotting BA flights to London until problems at the new terminal were sorted out.

Yesterday a couple were getting married at The Courtyard restaurant in Kenmore, Perthshire, with some 14 family and friends from overseas unable to make it because of the Terminal 5 issues.

Some of the stranded guests, who were flying from as far away as Australia and the US, were not expected to make it to Scotland before returning home.

The Conservatives called for an inquiry into the "chaos and confusion", while the British Chambers of Commerce said T5 was a "PR disaster for London and the UK".

The GMB union asked the public not to take out their frustrations on BA staff who were "doing their best to cope with what looks like technical difficulties".

Meanwhile, Richard Branson's Virgin Atlantic said 200 BA passengers had already switched across to longhaul Virgin flights because of the problems.