Government plans also include a "rapid resolution scheme" to allow most job disputes to be settled more quickly.
Business Secretary Vince Cable said he wanted to help firms expand without making existing staff feel insecure.
Unions say the move will make it harder to bring legitimate claims.
But business leaders have welcomed the proposed changes to employment legislation being outlined by Mr Cable, which the government says will save more than £10m and benefit employers to the tune of £40m.
The key points include:a consultation on "protected conversations", which would allow employers to have frank discussions about poor performance with workers without fear that they could be used as evidence in a tribunala "call for evidence" on the length of time required for a consultation period on planned redundancies. It is currently 90 days, but the government is considering reducing that to 30a requirement for all claims to go to the conciliation service Acas before reaching employment tribunaloptions for a "rapid resolution scheme" for more simple cases to be settled within three months
The business secretary will also confirm plans to make people work two years before they can make a claim for unfair dismissal from April - up from one year at present.
Mr Cable said the reforms would not erode workers' rights but would cut "unnecessary bureaucracy" and reduce the number of cases going to employment tribunal, which have risen 40% in the past three years.
"We are not trying to create an environment of 'hire and fire' and insecurity, absolutely not. That is not the way we want to proceed," he told BBC Breakfast. "In current conditions that would not be helpful at all."
"But we also want to create an environment in which entrepreneurs want to start businesses, expand, take on staff and feel confident that they can do that and, if they run into difficulties with a particular employee, they can have a conversation with them without worrying they are going to be taken to a tribunal."'Weeded out'
Business group the CBI welcomed the changes and called for them to be implemented quickly.Adam Marshall, director of policy at the British Chambers of Commerce, said: "Mandatory Acas involvement and new claimant fees will make the system fairer by ensuring that baseless claims are weeded out, and the pressure to settle is reduced.
"The proposal to investigate a fast-track scheme for simple claims could also help.
"Once these reforms are in place, firms won't have to waste time and money and can focus on running their business and delivering growth instead. It will also mean that genuine grievances get a better hearing."
But Paul Kenny, general secretary of the GMB union, said the agenda was "being driven by the CBI, who want the balance of power in the workplace tilted even more against the ordinary worker".
"These changes will make it harder for hundreds of thousands of workers to bring cases of victimisation, unfairness and bullying at work," he said.'Retrograde step'
"This will just sweep abuse under the carpet."
Mr Kenny also said a plan to require only one judge to preside over unfair dismissal cases was "retrograde" as it would remove "the voice of business and the shop floor" from proceedings.
Shadow business secretary Chuka Umunna said Labour agreed the tribunal system needed reform.
But he said: "Watering down people's rights at work by doubling the service requirement to claim for unfair dismissal from one to two years is not a substitute for a credible plan for growth.
"Instead of seeking to make it easier to fire people the government should be looking to make it easier to hire people at a time when their reckless economic policies have pushed up unemployment to a 17-year high."
Some 218,000 claims were received by employment tribunals last year.
A recent government-commissioned report suggested that unproductive workers should lose their right to claim unfair dismissal.
But the Lib Dems rejected the proposals from the businessman and Conservative donor Adrian Beecroft, saying they would not help the labour market at a difficult time for the economy.