Bus and train groups Arriva and National Express both issue trading updates on Tuesday, just days after transport minister Norman Baker attacked the companies and other members (FirstGroup, Stagecoach and Go Ahead) of the 'big five' transport groups for taking passengers for a ride. According to a report by LEK Consulting the five main bus operators' operating margins of 11.2% are nearly double those of their smaller rivals. That does not tie up with the view of Go Ahead Group which last week said the travel industry is going through a difficult period and both Arriva and National Express are also likely to bang on about tough times, increased fuel costs and the effect on revenues of rising unemployment.National Express's complaints of hard times certainly have an air of legitimacy as the company had to walk away from one of its rail franchises last year. The group recently appointed Dean Finch, the former boss of Tube Lines, as its chief executive and he has pledged to be very "hands on" as he seeks to turn the company's fortunes around. Bid target Arriva said back in May that revenue growth in its UK Trains division had continued to recover. CrossCountry passenger revenue was up by 8.9% in the 15 weeks to 25 April. Passenger revenue in Arriva Trains Wales was up 10.8% for the same period. UK Bus revenue increased 2.7% in the period to 16 April. Revenue in the Mainland Europe division, expressed in euro, declined by 5.3%.Outsourcing specialist Serco makes a pre-close trading statement which may include some commentary on the spending cuts announced in the Budget and how they are likely to affect the company.The Budget also presented some opportunities for the company, as well, however, according to UBS."There will be market interest in the status of opportunities within the new government, especially the Welfare to Work programme, where there is some uncertainty about scope and bid process," said UBS analyst William Vanderpump.INTERIMSPorvair, Pursuit Dynamics, Terrace Hill, TravelzestINTERNATIONAL ECONOMIC ANNOUNCEMENTSABC Consumer Confidence (US) (22:00)Business Climate Indicator (EU) (10:00)Industrial Confidence (EU) (10:00)Consumer Confidence (US) (15:00)Consumer Confidence Indicator (EU) (10:00)Consumer Confidence Indicator (FRA) (07:45)Economic Sentiment Indicator (EU) (10:00)PMI Retail (EU) (09:00)PMI Retail (GER) (08:55)Household Spending (JPN)Jobless Rate (JPN)Industrial Production (JPN)FINALSAssura Group, Carpetright, e-Therapeutics, Latham (James), Plastics Capital, Private and Commercial, ReNeuron, Scott WilsonANNUAL REPORTPrologicAGMSAndes Energia, Archipelago Resources, BlackRock Absolute Return Strategies EUR Shares, BlackRock Absolute Return Strategies GBP Shares, BlackRock Absolute Return Strategies USD Shares, Caffyns, Caspian Holdings, Cattles, Cellcast, Chimei Innolux Corp GDR (Reg S), Comstar UTS GDR (Reg S), Crimson Tide, Horizonte Minerals, Investors Capital Trust 'A' Shares, iPoint-Media, JSC Polymetal GDR (Reg S), LiDCO, Longships, Pinewood-Shepperton, Platmin, Praesepe, Public Power GDR (Reg S), RAM Investment Group, Sistema-Hals GDR (Reg S), Somero Enterprises (Reg S), Takefuji Corp, Tdk, Tower Resources, Trans-Siberian Gold, Ultima NetworksTRADING ANNOUNCEMENTSArriva, National Express Group, SercoUK ECONOMIC ANNOUNCEMENTSBBA Mortgage Lending Figures (09:30)Consumer Credit (09:30)M4 Money Supply (09:30)M4 Sterling Lending (09:30)Mortgage Approvals (09:30)PMI Retail (09:30)