How might a Democrat victory in Congress affect US business?

Most Washington business lobbyists agree that the impact of Tuesday's midterm election will depend on the margin of victory. If Democrats win an overwhelming majority in the House of Representatives it will be seen as an endorsement of a left-leaning agenda espoused by Nancy Pelosi, the California congresswoman and would-be speaker. But a narrower victory - and, as many observers expect, failure to capture the Senate - would lend support to a more moderate agenda supported by the so-called Blue Dogs, centrist to conservative Democrats who will not antagonise business constituents.

One financial services lobbyist said: "It is going to be virtually impossible to get anything truly harmful to business passed. So either we are faced with a stalemate or very sensible grand coalition legislation."

A Democrat victory would have an impact on some specific industries and policy issues.

■Trade: A Democratic victory raises significant questions about the likelihood that Congress would renew President George W. Bush's trade promotion, or fast-track, authority (TPA), which expires next summer.

Some trade deals could still be approved by Congress, but Democrats would be likely to force the administration to negotiate tougher environmental and labour standards.

Bruce Josten, a top lobbyist at the US Chamber of Commerce, believes Democrats could grant Mr Bush limited authority on specific deals, including a trade agreement with South Korea and the Doha trade round. Democrats could also seek the appointment of a new "trade enforcement tsar" to oversee industries that are perceived to be hurt by trade deals.

Labour groups are likely to demand that countries negotiating free trade agreements abide by international labour standards.

■Insurance: Democrats are likely to renew the Terrorism Risk Insurance Act, post-September 11 legislation that provides a backstop to the insurance industry in the event of a catastrophic terrorist attack. Both Democrats and Republicans could also lend support to insurance companies' wish for an optional federal charter that would create a federal regulatory standard for insurance companies, instead of the current structure in which insurance groups are regulated state by state.

■Oversight: With enhanced oversight and subpoena power, some Democratic leaders are expected to pursue investigations of key industries and issues, including executive compensation, oil and gas companies, government contractors such as Halliburton, defence manufacturers, pharmaceutical companies and hedge funds.

■Energy and environment: Democrats are expected to promote heavily renewable energy sources and will pay for such measures by cutting tax subsidies to oil and gas groups. Some Democrats, such as Ms Pelosi, would also support the instalment of new fuel efficiency standards - but such a measure would likely not gain unanimous support.

Congressman John Dingell of Michigan, who would chair the House energy committee, is not expected to endorse new standards that could hurt the US car manufacturing industry, but might support new standards for other industries, such as utilities. Democrats would not support the opening of the Arctic National Wildlife Refuge and other areas to oil and gas exploration.

■Minimum wage: Democrats would support increasing the federal minimum wage, which has been stuck at $5.15 an hour for the past 10 years.

■Pharmaceuticals: Democrats in the House would support increased federal funding for embryotic stem cell research - a measure that could pass in the Senate but would face a veto by Mr Bush. Drug companies could be hurt by a proposal by Ms Pelosi and other Democrats to revamp the Medicaid prescription drug benefit in order to give the government bargaining power to keep drug prices low. It has been estimated that the move could save the US government $190bn over the next 10 years.

■Homeland security and defence: Democrats have promised to increase spending on border and port security as part of a multi-billion dollar project to screen all containers that enter the US. Defence companies have an ally in Democrat John Murtha, a critic of the war in Iraq but a likely supporter of a robust defence budget. Mr Murtha may be a candidate for majority leader, or could head defence appropriations.

■Tax: Ms Pelosi has vowed that Democrats will return to so-called "pay as you go" rules, in which spending increases must be matched by other cuts in spending or tax increases. The first Democrat target could be the "tax gap", roughly $345bn a year that is uncollected tax. Democrats would likely work with Republicans on broad reform.

■Media and communications: Democrats would likely increase scrutiny of the Federal Communications Commission, weighing in heavily on issues ranging from big communications mergers to the ongoing debate over media ownership limits - which Democrats do not believe should be loosened to allow for more consolidation. Democrats favour content providers such as Google in the battle for "net neutrality", a position that hurts telecommunications and cable companies.