Teachers and postal workers could both strike in separate rows over pay and pension changes.
Members of the National Union of Teachers (NUT) have voted for a one-day strike on 24 April. It would be its first national stoppage for 21 years.
The union wants the government to increase its 2.45% pay offer for 2008 to at least above inflation.
NUT general secretary Steve Sinnott said: “I call on the government to think again and ensure that salaries at least keep pay in line with inflation and that there is a recognition of the continuing workload pressures on teachers.”
The government said a strike would only disrupt children’s learning.
Strike action could again be on the cards at Royal Mail after postal workers overwhelmingly rejected the company’s pension changes.
In a ballot of 140,000 members of the Communication Workers’ Union (CWU), 92% of respondents voted against the changes, which would see the final-salary scheme closed to new members and the retirement age raised.
Royal Mail claim the proposed changes are essential to deal with a deficit of £3.4bn in its pension scheme and the union agreed to them last year.
The CWU ballot result follows Royal Mail managers’ rejection of the pension changes two weeks ago.
Dave Ward, CWU deputy general secretary, said that strike action would be “inevitable” if the dispute was not resolved. “The result of this ballot clearly demonstrates that Royal Mail’s pension consultation was a sham,” he added.
The pensions dispute follows a long-running row over pay and working practices last year that saw several walk-outs and strained industrial relations.