At present Deloitte, the only Big Four firm which has not hived off its consulting arm, continues to dominate UK consulting revenues, despite a 6.9% decrease in fees to £299m. With total income from all service lines at £1.25bn, advisory work accounts for almost a quarter of the firm's business.

But this is relatively poor growth for Deloitte when compared to the impressive figures presented in the 2003 survey, when the firm recorded a massive 58% increase in consulting work.

An explanation for this seems to come from the medium-sized and smaller players in the market. For the first time, the growth figures suggest that mid-tier firms are starting to steal consulting work from the Big Four, which are still hampered by conflict of interest issues, with smaller firms picking up significant scraps.

Top of this pile is Robson Rhodes, ranked twelfth this year, which increased its consultancy fees by 57% to £11m, compared to just a 1% rise last year.

Chantrey Vellacott, meanwhile, made a complete about-turn, seeing 25% growth in its advisory services compared with a fall of almost 70% last year.

Similarly, Vantis, the listed accountancy consolidator, also managed to increase consulting revenues by 25%, taking earnings to £5m following on somewhat less dramatically, from last year's 90% increase.

Small firms that showed a significant upturn in consulting revenues include Littlejohn Fraser, DTE and Mercer & Hole, with increases of 50%, 30% and 23% respectively.

The tax picture is relatively unchanged despite the government's clampdown on tax avoidance, with the Big Four and mid-tier firms facing scrutiny of tax work provided to clients.

Despite this threat, Deloitte was again the Big Four firm that yielded the biggest growth as tax revenues grew by 14% to £374m, although it was way off the 77% boom in tax revenues recorded last year.

PwC, which has provided its tax revenue figures for the first time, saw a drop of 12%. Although, with almost £500m earned from this service line, it remains streets ahead of the other players in the market.

The mid-tier firms' income from tax work changed little, at least among the bigger firms, with Grant Thornton, BDO Stoy Hayward and Smith & Williamson recording increases of between 3% and 5%. PKF remained unchanged, while Baker Tilly saw tax revenues fall by almost 5%.

Tenon, the troubled consolidator, saw its tax business fall dramatically for the second year running, dropping by 52% to just £3m, following last year's 69% plunge.

By contrast, its smaller listed rival Vantis made significant inroads in this area, increasing tax fees by 25% to £5m. Among the smaller firms, Francis Clark, WBS and DTE recorded growth in tax revenues of 25%, while Haslers, the 47th biggest firm, saw gains of 50% as revenues hit £4.3m.