The number of days lost to industrial action in Britain almost doubled between 2003 and 2004, although the number of strikes were the lowest on record.
Official figures from the Office for National Statistics (ONS) found that working days lost in 2004 totalled 904,900, almost double the 499,100 working days that were lost in 2003 but lower than the 1.3 million working days lost in 2002.
The figures, from the June edition of Labour Market Trends, found that the number of working days lost in 2004 was higher than the annual average for 1994-2003 (560,200) but considerably lower than the annual average of 7.2 million in the strife-torn 1980s and 12.9 million in the 1970s.
However the number of work stoppages fell to 130 in 2004, the lowest on record. This compares with 133 stoppages in 2003 and 146 stoppages in 2002.
But the number of workers involved in labour disputes almost doubled from 150,600 in 2003 to 292,700 in 2004.
The increase was almost entirely due to a strike last November by 200,000 public sectors workers over plans to cut some 100,000 civil service jobs.
Overall, half (48 per cent) of the working days lost in 2004 were in public administration and a further 42 per cent in education. The remaining five per cent of days lost were in transport, storage and communication.
Susan Anderson, director of human resources at the Confederation of British Industry (CBI) said that this resurgence of militancy by public sectors was worrying.
"The growth in the number of days lost is primarily down to a small number of disputes in the public services, some involving very large numbers of people," she said
But Britain's biggest trade union, the T&G, said that it saw no increase in ultra-militant unions or employers being overly aggressive and pointed out that the figures were skewed by the sheer number of civil servants who walked out last November.
The ONS added that 12,400 working days have been lost through strikes between January and March this year from 18 stoppages involving more than 10,000 workers.