Figures from the Office for National Statistics (ONS) showed that the number of people out of work and claiming unemployment benefit rose by 9,700 last month to 950,800, the highest monthly rise in more than a decade.
The total number of people out of work in the three months to April also rose by 36,000 on the previous quarter to 1,495,000.
But despite the rises, the ONS said the number of people in employment remained at its highest level since records began in 1984, rising 51,000 over the previous quarter to 27.87 million.
The statistics show that the claimant rate of 3.1 per cent has remained unchanged over the past 16 months. The UKís overall employment rate of 5.1 per cent is also lower than most other developed economies.
But the manufacturing sector continued to suffer, with the number of jobs in the sector falling by 3.7 per cent to 3.53 million, the lowest figure since records began in 1984.
The ONS said that the explanation for both joblessness and employment rising is largely due to the large number of women entering the workforce for the first time.
Figures released earlier this week by Deloitte and Touche and the Recruitment and Employment Confederation showed that demand from employers for both permanent and temporary staff is continuing to contract, with no sign of a post-Iraq bounce rescuing the labour market. Demand for staff in manufacturing fell for the forty-third month in a row.
But a separate survey of 3,100 UK businesses by TMP/Hudson Global Resources suggests that overall business confidence may be rising. More than a third of employers said that they would be hiring new staff over the next six months with only 15 per cent planning to make redundancies.