Around 1.97 million people in the UK are currently unemployed
There is an average of 10 jobseekers for every vacancy advertised in UK jobcentres, the TUC has warned.
The trade union body said the ratio - which applies to unemployed people who are claiming jobseeker allowance - had more than doubled over the past year.
The TUC said that while 10 unemployed people were chasing every advertised job in January of 2009, a year earlier it was only four per vacancy.
In 25 council areas there were now more than 20 people per job, it added.
'Shocking jobs fall'
The TUC said the Isle of Wight was the worst hit area, and now had a ratio of 60 jobseekers per advertised vacancy.
It was followed by Scotland's Western Isles, 44, and Blaenau Gwent, 42, and Rhondda, Cynon, Taff, 36.
Two London boroughs came next, with Hackney on 36, and Lewisham on 34.
The TUC said it had come to its figures by analysing official data.
The Office for National Statistics is now expected to say on Wednesday that UK unemployment went above two million between January and March.
"Rising unemployment has been matched by an equally shocking decline in job vacancies," said TUC General Secretary Brendan Barber.
"The government can no longer claim there is plenty of work available when there are as many as 20 dole claimants per jobcentre vacancy in parts of the country."
The TUC's figures came as a separate report by accountants BDO Story Hayward said one in every 56 UK businesses will fail in 2009, a 59% rise on last year.
JOBSEEKERS PER VACANCY
Isle of Wight - 60
Western Isles - 44
Blaenau Gwent - 42
Rhondda, Cynon, Taff - 36
Hackney - 36
Lewisham - 34
Argyll & Bute - 31
Greenwich - 30
Lambeth - 29
South Tyneside - 28
The British Chambers of Commerce (BCC) estimated last week that UK unemployment would reach 3.2 million - or just over 10% of the workforce - by the second half of next year.
BCC director general David Frost said the government had to do more to help firms of all sizes.
Unemployment is rising as the UK recession, the first since 1991, continues.
UK economic output fell by 1.5% in the last three months of 2008, after a drop of 0.6% between July and September. This met the widely accepted definition of a recession - two consecutive quarters of negative economic growth.