Davis has already reached the Olympic standard in the US

Davis was only given a British passport three days ago after seeking dual citizenship through his mother, who was born in London 25 years ago.

And in his first-ever race on British soil, he qualified for the 400m final at the Olympic trials in Manchester.

"It's been a hectic week," said the 26-year-old. "I just hope I can get over my jet-lag in time for the final."

Davis won the opening heat of the 400m in 46.10 seconds to reach Sunday's final in the Manchester Regional Arena.

Yes, I may deprive someone of an Olympic place but emotions are always high in an Olympic year Malachi Davis

But his presence has already divided opinion, with several athletes reportedly unhappy he has been allowed to run.

"I know a lot of athletes are very bitter and they say he shouldn't be here," said Jamie Baulch, who missed out on a place in the final.

"I am not really bitter, however, because I think it helps make the British team stronger for the Olympics."

Davis added: "Yes, I may deprive someone of an Olympic place but emotions are always high in an Olympic year.

"It's all down to the best athletes to qualify and I do have a lot of respect for the one-lap runners in the UK.

400m FINAL LINE-UP Malachi Davis, Daniel Caines, Sean Baldock, Tim Benjamin, Jared Deacon, Conrad Williams, Graham Hedman, Robert Tobin

"It is difficult to ask me where my allegiances lie as I have an American father and British mother, it is like asking which parent I like most."

Max Jones, performance director for UK Athletics, said he was happy for Davis to be competing in Manchester.

"What he has done is all perfectly legal," said Jones.

"We have had people in similar circumstances ring up before saying they are getting a British passport and wanting to compete for us, but nothing has come of it.

"Obviously some of the other 400m runners will feel a little miffed because they have been preparing for six years for these Olympics."

Davis said he only began thinking about representing Britain after speaking to close friend Felix Sanchez.

The 400m hurdles world champion, who was born in America but runs for the Dominican Republic, suggested Davis took advantage of his opportunity to claim dual citizenship.

Every athlete envisages competing at the highest level and everyone back home is behind me 100% Malachi Davis

"I received my British passport on Thursday and then jumped on a flight at 6pm," said Davis.

"This is my first time in England - in fact I only left America for the first time a couple of weeks ago when I raced in Vancouver, Canada - and it is a beautiful country.

"It is very cold but the crowd and the energy is terrific.

"I barely qualified for the US trials and was only made aware of the possibility of running for Britain when Felix said I'd be better off running for this country.

"Every athlete envisages competing at the highest level and everyone back home is behind me 100%."