Maken said Delhi being the national capital is "fully" funded by the Union government and that the tax burden on its people will increase if it becomes a state.
"The salary of the Delhi Police alone is Rs 8,000 crore per year. The Union government spends more than Rs 3,000 crore a year on five-six super specialty hospitals in the city. The local administration doesn't have to pay a single penny," he told PTI.
Petrol prices in Delhi are the lowest as compared to all other metros in the country because the central government bears most of the cost of fuel subsidy, he said.
"Why should the people of Delhi pay more tax just because Arvind Kejriwal wants more power?" the Congress leader asked.
"It will be a disaster for Delhi. The city will become as bad as Bihar, Uttar Pradesh or any other state. Do you think Ghaziabad, Noida, Gurgaon and Begusarai are better than Delhi in terms of law and order?" he said.
Maken, who has represented the New Delhi seat twice, also claimed there's massive discontent among government employees over the seventh pay commission recommendations.
"The seventh pay commission says there will be no pay commission in the future. The government has accepted this recommendation. What can be worse than this?" he asked.
"The first thing we will do is we will remove this recommendation and ensure that the eight pay commission is set up in time," he said.
The fifth and the sixth pay commissions recommended a 40 percent hike in salary. The seventh pay commission gave a meager 14 percent hike, Maken said.
He said the seventh pay commission also recommended abolishing 36 interest-free advances, like festival and vehicle advance, given to government employees.
"Some of these advances were restored by the government, but others were not. We will bring them back," the Congress leader added.
On his BJP rival Meenakshi Lekhi's allegation that his "shoddy" work as Union urban development minister is responsible for the sealing chaos in Delhi, Maken said he had brought in a legislation to stop sealing within a week in May 2006.
"I got more than 170 amendments (done) to Delhi's master plan. Why can't the BJP government do so if there's something wrong with it? I was the urban development minister in 2006. How can I be held responsible?" he asked.
The Congress leader also alleged that the BJP-ruled New Delhi Municipal Council had failed to regularise muster roll employees in the last five years.
Asked if he accords priority to pollution as an election issue, Maken claimed that in 2004, he became the first person in the country to include environment in his poll campaign.
The Congress leader said that as Delhi's transport minister, he oversaw the transition of the national capital's entire public transport system from diesel to CNG.
"The environment is a state subject because it is related to public transport. The main reason for depleting air quality in Delhi is vehicular pollution. The rise in the number of private vehicles is worsening the situation," he said.
"In 2013, we had 5,400 DTC buses. The number has come down to 3,500. The total passenger trips per day have also come down drastically, from 48 lakh in 2013 to 26 lakh now. So, 22 lakh passengers are using their personal transport, hence more air pollution," he said.
"The construction of the Delhi Metro has also slowed down. The government is yet to approve the detailed project report for the fourth phase," he added.
Asked if the Congress failed to build on the momentum it gained after winning three state assembly elections in December last year, Maken said the party has gone from strength to strength and put up its best candidates everywhere for Lok Sabha polls.
On alliance with regional parties, he said barring UP and Delhi, the Congress has stitched strong coalitions in almost all states.
"We have a strong alliance in Jharkhand, Bihar and Maharashtra. We have tie-ups at all the places where it matters the most," he said.
He criticised Telangana Chief Minister K Chandrashekar Rao for trying to form an anti-BJP, anti-Congress front.
"All such people who talk about such a front are tacitly supporting the BJP. At the national level, it is only the NDA versus the UPA," he said.
On the prospects of the Congress forming the next government, Maken said, "No one gave us a chance in 2004. Our party came to power despite the 'India Shining' wave in favour of the BJP. Sonia Gandhi has said that 2004 will be repeated."
"We will win all seven seats in Delhi and will be able to form a government at the Centre," he added.